Ubuntuland & The Dream Planet

KStars Guide the feature-rich planetarium: Astronomical Device Control with INDI, Configuration, Concepts.

2026-10-07T08:37:00.000-05:00

You can run CCD and Video Capture devices from the Tools → Devices → Device Manager... menu item. Like all INDI devices, some of the device controls will be accessible from the skymap. The device can be controlled fully from the INDI Control Panel... item.

The standard format for image capture is FITS. Once an image is captured and downloaded, it will be automatically displayed in the KStars FITS Viewer.

Configure INDI

The INDI page allows you to modify Client side INDI specific options. To access it, select the INDI page from Settings → Configure KStars... menu item. The window is divided into several main categories: General, Device Updates, Display and Server Port:

INDI Concepts

The main key concept in INDI is that devices have the ability to describe themselves. This is accomplished by using XML to describe a generic hierarchy that can represent both canonical and non-canonical devices. In INDI, all devices may contain one or more properties. Any property may contain one or more elements. There are four types of INDI properties:

Text property.

Number property.

Switch property (Represented in GUI by buttons and checkboxes).

Light property (Represented in GUI by colored LEDs).

For example, all INDI devices share the CONNECTION standard switch property. The CONNECTION property has two elements: CONNECT and DISCONNECT switches. KStars parses the generic XML description of properties and builds a GUI representation suitable for direct human interaction.

The INDI control panel offers many device properties not accessible from the sky map. The properties offered differ from one device to another. Nevertheless, all properties share common features that constrains how they are displayed and used:

Permission: All properties can either be read-only, write-only, or read and write enabled. An example of a read-write property is the telescope’s Right Ascension. You can enter a new Right Ascension and the telescope, based on current settings, will either slew or sync to the new input. Furthermore, when the telescope slews, its Right Ascension gets updated and sent back to the client.

State: Prefixed to each property is a state indicator (round LED). Each property has a state and an associated color code:

Table 9.1. INDI State color code

INDI State color code

State

Color

Description

Idle

Gray

Device is performing no action with respect to this property

Ok

Green

Last operation performed on this property was successful and active

Busy

Yellow

The property is performing an action

Alert

Red

The property is in critical condition and needs immediate attention

The device driver updates the property state in real-time when necessary. For example, if the telescope is in the process of slewing to a target, then the RA/DEC properties will be signaled as Busy. When the slew process is completed successfully, the properties will be signaled as Ok.

Context: Numerical properties can accept and process numbers in two formats: decimal and sexagesimal. The sexagesimal format is convenient when expressing time or equatorial/geographical coordinates. You can use any format at your convenience. For example, all the following numbers are equal:

-156.40

-156:24:00

-156:24

Time: The standard time for all INDI-related communications is Universal Time UTC specified as YYYY-MM-DDTHH:MM:SS in accord with ISO 8601. KStars communicates the correct UTC time with device drivers automatically. You can enable/disable automatic time updates from the INDI page in the settings dialog.

General

INDI server: Specify the binary of installed INDI server in your system. By default, KStars uses “/usr/bin/indiserver” binary.

INDI drivers XML directory: Specify the XML directory where INDI drivers are located in your system. By default, KStars uses “/usr/share/indi” directory.

Default FITS directory: Specify the directory where all captured FITS images will be saved to. If no directory is specified, images will be stored in $HOME.

Time & Location Updates

KStars updates all devices: KStars is the master source for time and location settings. All INDI devices time and locations settings are synchronized to KStars settings.

Mount updates KStars: Mount handset is the master source of time and location settings. KStars time and location settings are synchronized with controller settings.

GPS updates KStars: GPS driver is the master source of time and location settings. KStars time and location settings are synchronized with GPS settings.

Time: Synchronize KStars date and time automatically from the update source.

Location: Synchronize KStars location settings from the update source.

Display

Telescope crosshair: When checked, KStars displays the telescope’s target crosshair on the sky map. The crosshair is displayed upon a successful connection to the telescope and its location is updated periodically. The telescope’s name is displayed next to the crosshair. KStars displays one crosshair per each connected telescope. To change the color of the telescope’s crosshair, open the Configure - KStars window. Select the Colors page, and then change the color of the Target Indicator item to the desired color.

Independent window: Make FITS Viewer window independent.

Message notifications: Show INDI messages as desktop notifications instead of dialogs.

Server Port

Specify range of ports that INDI Server will bind to when starting new drivers.

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Audio User Guide for Ubuntu Studio

2026-10-04T14:21:00.000-05:00

PulseAudio is a powerful, network-capable sound server for POSIX-compliant operating systems (primarily Linux) that acts as a middleman between applications and hardware. It enables advanced features like per-application volume control, on-the-fly audio routing, and network streaming, making it the standard audio subsystem in most modern desktop Linux distributions.

Pulseaudio - The Desktop Sound System

What is pulseaudio?

Pulseaudio is the default sound system on Ubuntu Studio, and handles all desktop sound. It uses alsa as its backend, meaning alsa provides the drivers for your soundcard.

Controlling pulseaudio is done mainly from the volume control in the indicator area. But, for some cards, not everything can be adjusted from there and you will need to use the generic alsamixer or a special mixer (mentioned below) to get further control of your audio device.

Supported Devices

Alsa provides driver support

Any device that is supported by alsa is potentially supported by Pulseaudio. Usually only pro audio multichannel cards may have problems with pulseaudio. If you find that your multichannel card is not working with pulseaudio, but is supported by alsa, it will still work perfectly with jack. To get desktop audio working for such a card, you will need to set up the pulseaudio to jack bridge mentioned below.

Firewire will only work with special configuration

Currently, firewire devices are not supported by alsa, and may only be used with jack using the ffado firewire driver. But, since we are now able to connect Pulseaudio to jack, using the pulseaudio to jack bridge, we can circumvent this problem.

No Volume?

Many cards are muted by default, and need to be accessed with a special mixer in order to be controlled. There is a generic alsa mixer in the main menu at menu -> Audio Production -> Mixers -> Mixer . To use it, you will first need to select the card you wish to control, and make its controls visible from Select Controls. If I for example want to raise volumes for a m-audio delta device, I will first need to make all the ADCs (Audio to Digital Converter) and DACs (Digital to Audio converter) visible to control the volume for inputs and outputs.

Pci mixers

There are also card specific mixers. They are not actually "brand" specific, but "chip" specific, so some mixers will work with many brands that share the same internal chip. These mixers are not only needed to control your device with pulseaudio, but also with jack, since both use alsa as its' backend.

To find out which chip your pci audio device has, look up the brand here. Select it, and try to find the chipset for your model. One particularly common chipset is the envy24(ice1712).

Here's a list of mixers for pci devices that are preinstalled with Ubuntu Studio (comes with the alsa-tools package):

echomixer is the Linux equivalent of the Echoaudio console application from Echoaudio. It is a tool to control all the features of any Echoaudio soundcard. This includes clock sources, input and output gains, mixers, etc.

hdspmixer is the Linux equivalent of the Totalmix application from RME. It is a tool to control the advanced routing features of the RME Hammerfall DSP soundcard series. To handle RME Hammerfall cards you might also need the tools hdspconf and hdsploader

mudita24 - is a control tool for Envy24 (ice1712) based sound cards, and replaces the older envy24control (M-Audio Delta Series)

rmedigicontrol - is a control tool for RME Digi32 and RME Digi96 sound cards. It provides a graphical frontend for all the sound card controls and switches.

More Information

More information on supported hardware can be found here.

Jack - The Pro Audio Sound System

Jack is a sound server, and like pulseaudio, it is able to use alsa as it backend. But, jack is also able to use other drivers, such as the firewire driver developed by ffado. Commonly, those are the only two drivers used with jack for audio devices on a Linux machine.

Why use Jack?

Many audio applications will only work with jack - Applications meant for pro audio use will often only work with jack.

Jack is extremely low latency capable - Jack is able to give you extremely low latencies at the right conditions. Which is a must if you are to play a live software instrument.

Some devices will only work with jack - As mentioned above, firewire devices will only work with jack.

Jack connectability - When using jack you can connect any application to any other application just as if you were using physical cables. You are thus not restricted by the functionality of a single application. You can even route pulseaudio to jack, and make use of all of it's desktop audio capability.

Starting Jack

The easiest way to start jack is to use Ubuntu Studio Controls. To learn more, a guide to Ubuntu Studio Controls can be found here.

Firewire Troubleshooting

Sometimes it's just a matter of knowing what to do in which order. Maybe you need to start your computer with the firewire device already attached, or the other way around. Try different combinations, if you are sure the device is supported. (more info on supported devices here).

USB troubleshooting

A common thing to try is to set Jack Periods to 3 in Ubuntu Studio Controls.

Reducing Xruns

Xruns are either a buffer overflow or buffer underflow of the audio system in Jack. These can be heard as a popping or a ticking sound. Reducing or eliminating Xruns can be done with multiple methods, such as:

Turning off and using a wired network connection
Turning off bluetooth
Disabling the PulseAudio-Jack bridge
Reduce background processes

If none of these methods work, the only way to reduce or eliminate Xruns is to raise your buffer to a higher setting.

Sepia Search is the official search engine for PeerTube

2026-09-27T14:23:00.000-05:00

Sepia Search is indeed the official search engine for PeerTube, developed and maintained by Framasoft, the same French non-profit organization behind the PeerTube software itself.

Because PeerTube is decentralized (made up of thousands of independent "instances"), there isn't naturally a single "home page" like YouTube. Sepia Search was created to solve this by providing a central gateway to discover content across the entire federation.

Key Facts About Sepia Search

Mascot Connection: The name comes from Sepia, the PeerTube mascot (a cuttlefish).
Opt-in Philosophy: It doesn’t automatically index every PeerTube site. Instance administrators can choose whether or not to be included in the search results.
Moderation: Unlike the decentralized instances which set their own rules, Sepia Search is moderated by Framasoft to ensure results comply with their terms of service (e.g., removing content that promotes hate speech or illegal acts).
Open Source: True to the project's roots, the code for the search engine is completely open source, meaning anyone can host their own alternative version with different indexing rules.

Since PeerTube is decentralized, your journey depends on whether you want to be a resident (joining someone else's instance) or a landlord (hosting your own).

1. Joining an Existing Instance (Easier)

If you just want to upload videos or interact with others, you should join a pre-existing community. Each instance has its own rules, storage limits, and moderation.

How to find one: Visit joinpeertube.org/instances. You can filter by:
- Topic: (e.g., Gaming, Music, Science & Tech)
- Language: (English, French, Spanish, etc.)
- Registration Policy: Look for "Open" if you want to sign up immediately. Some require an application.
Recommendation for 2026:
- FUTO: A high-performance instance focused on tech and digital freedom.
- Diode Zone: Great for creators focused on electronics, making, and DIY projects.
- TilVids: A popular educational and high-quality "edutainment" instance.

2. Hosting Your Own Instance (For Tech-Savvy)

Hosting your own gives you total control but requires maintenance. As of late 2025/early 2026 (PeerTube v8.x), the process is more streamlined but still technical.

Technical Requirements

Server (VPS): At least 2GB RAM (4GB recommended) and a modern CPU.
OS: Most people use Debian or Ubuntu.
Domain Name: You’ll need a custom domain (e.g., video.yourname.com).
Storage: Video files are huge! Most admins use S3-compatible Object Storage (like Wasabi or Backblaze B2) to keep their local server disk from filling up.

Two Ways to Install

The "Pro" Way: Follow the Official Production Guide. It involves setting up PostgreSQL, Redis, Nginx, and Node.js manually.
The "Easy" Way: Use YunoHost or Docker.
- YunoHost is a server operating system designed for self-hosting that lets you install PeerTube with basically one click.
- Cloudron is another "app store for servers" that handles the updates and backups for you for a small fee.

Which path sounds better for you?

"I just want to upload videos": I can help you find a specific instance that matches your niche (like art, gaming, or coding).
"I want to run the show": I can walk you through the first few commands to set up a VPS for your own instance.

KStars Guide the feature-rich planetarium: Astronomical Device Control with INDI, Introduction, Telescope Setup.

2026-09-24T08:34:00.000-05:00

KStars provides an interface to configure and control astronomical instruments via the INDI protocol.

The INDI protocol supports a variety of astronomical instruments such as CCD cameras and focusers. For an up to date list of supported devices, please visit INDI supported devices page.

INDI Setup

Telescope Setup

Most telescopes are equipped with RS232 interface for remote control. Connect the RS232 jack in your telescope to your computer’s Serial/USB port. Traditionally, the RS232 connects to the serial port of your computer, but since many new laptops abandoned the serial port in favor of USB/FireWire ports, you might need to obtain a Serial to USB adaptor to use with new laptops.

After connecting your telescope to the Serial/USB port, turn your telescope on. It is highly recommended that you download and install the latest firmware for your telescope controller.

The telescope needs to be aligned before it can be used properly. Align your telescope (one or two stars alignment) as illustrated in your telescope manual.

KStars needs to verify time and location settings before connecting to the telescope. This insures proper tracking and synchronization between the telescope and KStars. The following steps will enable you to connect to a device that is connected to your computer. To connect and control remote devices, please refer to remote device control section.

You can use the Telescope Setup Wizard and it will verify all the required information in the process. It can automatically scan ports for attached telescopes. You can run the wizard by selecting the Devices → Telescope Wizard menu item.

Alternatively, you can connect to a local telescope by performing the following steps:

Set your geographical location. Open the Set Geographic Location window by selecting the Settings → Geographic... menu item, or by pressing the Globe icon in the toolbar, or by pressing Ctrl+G.

Set your local time and date. You can change to any time or date by selecting Time → Set Time... menu item, or by pressing the Time icon in the toolbar. The Set Time window uses a standard KDE Date Picker widget. If you ever need to reset the clock back to the current time, just select the Time → Set Time to Now menu item.

Click on the Tools → Devices → Device Manager... menu item.

Under the Device column, select your telescope model.

Click on the Run Service button.

Click Close to leave the Device Manager Dialog.

Note

You do not need to set the geographic location and time every time you connect to a telescope. Only adjust the settings as needed.

You are now ready to use the device features, KStars conveniently provides two interchangeable GUI interfaces for controlling telescopes:

Controlling your telescope

Sky map Control: For each device you run in the Device Manager, a corresponding entry will show up in popup menu that allows you to control the properties of the device. You can issue commands like Slew, Sync, and Track directly from the sky map.

Here is a screenshot of the popup menu with an active LX200 Classic device:

INDI Control Panel: The panel offers the user with all the features supported by a device.

The panel is divided into three main sections:

Device tabs: Each additional active device occupies a tab in the INDI panel. Multiple devices can run simultaneously without affecting the operation of other devices.

Property views on the Main Control and Options tabs: Properties are the key element in INDI architecture. Each device defines a set of properties to communicate with the client. The current position of the telescope is an example of a property. Semantically similar properties are usually contained in logical blocks or groupings.

Log viewer: Devices report their status and acknowledge commands by sending INDI messages. Each device has its own log view. A device usually sends messages to its device driver only, but a device is permitted to send a generic message when appropriate.

You are not restricted on using one interface over another as they can be both used simultaneously. Actions from the Sky map are automatically reflected in the INDI Control Panel and vice versa.

To connect to your telescope, you can either select Connect from your device popup menu or alternatively, you can press Connect under your device tab in the INDI Control Panel.

Important

By default, KStars will try to connect to the /dev/ttyS0 port. To change the connection port, select the Tools → Devices → INDI Control Panel... menu item and change the port under your device tab.

KStars automatically updates the telescope’s longitude, latitude, and time based on current settings in KStars. You can enable/disable these using the INDI page from the Settings → Configure KStars... menu item. Using the INDI page you can configure KStars to display or not INDI status messages in the status bar. By default INDI server port numbers have values between the range from 7624 to 9000, but you can easily change the range using the From: and To: text boxes from the Server Port section.

If KStars communicates successfully with the telescope, it will retrieve the current RA and DEC from the telescope and will display a crosshair on the sky map indicating the telescope position. You can hide the crosshair that marks telescope position using INDI page from the Settings → Configure KStars... menu item.

Note

Synchronizing your telescope

If you aligned your telescope and the last alignment star was, for example, Vega, then the crosshair should be centered around Vega. If the crosshair was off target, then you can right-click Vega from the sky map and select Sync from your telescope menu. This action will instruct the telescope to synchronize its internal coordinates to match those of Vega, and the telescope’s crosshair should now be centered around Vega.

This is it: your telescope is ready to explore the heavens!

Warning

Never use the telescope to look at the sun. Looking at the sun might cause irreversible damage to your eyes and your equipment.

KStars can control local and remote devices seamlessly via the INDI server/client architecture. INDI devices may be run in three different modes:

Local: The local mode is the most common and is used to control local device (i.e. a device attached to your machine).

Server: The server mode establishes an INDI server for a particular device and waits for connections from remote clients. You cannot operate server devices, you can only start and shut them down.

Client: The client mode is used to connect to remote INDI servers running INDI devices. You can control remote devices seamlessly like local devices.

You can run local device, establish INDI servers, and connect to remote clients from the Tools → Devices → Device Manager... menu item.

Here is a screenshot of the Device Manager window:

You can run devices by browsing the device tree, selecting a specific device, and then clicking on the Run Service button. You can select the operation mode, either local or server as defined above. The port number is randomly generated between the range from 7624 to 10,000. To specify a port, click on the port column next to the desired driver. KStars allows multiple drivers to run under one INDI server, and hence one port. Select multiple drivers then press Run Service button.

To control remote devices, refer to the remote device control section.

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How to install Ubuntu Budgie

2026-09-20T10:22:00.000-05:00

Ubuntu Budgie is a Ubuntu flavor using desktop environment called Budgie. Budgie is a desktop environment focused on having a clean and yet powerful desktop without unnecessary bloat.
Before installing, check the minimum specified hardware, so that you can have flawless experience. Here are the minimum specs for running Ubuntu Budgie:

System Requirements

Processor speed: 2.4Ghz
Memory: 4GB of RAM
Hard Disk space: 60GB

Note:

In 90% of cases you are good to go with those and specs above. However, some machines have specific hardware that requires you to check the driver before installation which is usually related to Broadcom Network cards found in laptops.

Before installation prepare the installation medium. You can choose either CD or DVD or use USB to serve as one. If you are using CD or DVD, use your favorite CD/DVD writer app to write the image to it. Windows users can use ImgBurn or Nero Burner and other similar burner apps. Mac users can use Etcher. If you are using USB as your installation medium you can use UNetBootin to make bootable USB installation drive.Here are some tools that you can use to make bootable USB:

USB Tools

Rufus – Windows only
Universal USB Installer
UnetBootin
Ubuntu Startup Disk Creator
RMPrepUSB
Etcher – Multi-platform – Recommended for new users
WinSetupFromUSB
RMPrepUSB

Since there is not yet Ubuntu Budgie as an option you must select Diskimage option, and then specify path to where you’ve downloaded iso. (Usually Downloads folder) Choose your USB drive and click ok. Note: When using Windows, be sure to check if UnetBootin has selected the correct drive letter. Failure to do so may result in loss of data. After you click ok, UnetBootin will start extracting ISO to USB. Congratulation, if everything went right you’ve made your bootable installation USB drive.

After you’re done with making bootable medium, restart your computer and choose to boot from bootable USB drive. To boot from bootable USB drive press F8 and select your USB which will be presented alongside other HDD and CD-DVD drives. Note: Some computers and laptops, depending on the Motherboard have different function key assigned to access bootable menu. Some will show how to access boot options while booting, while others will require you to check each button by doing trial and error until you find the right one. If any of button doesn’t have that function, head over to BIOS settings by pressing DEL button while booting, and go to Boot Device settings. Depending on your motherboard and BIOS software, this may be called something different. After you load the live version of Ubuntu Budgie, you can choose to load the operating system for testing and preview by pressing “Try Ubuntu Budgie without installing”, or press “Install Ubuntu Budgie” to go straight for installation. If you’ve chosen first option, you will be still able to install the UB by pressing Install Ubuntu Budgie icon located on desktop.

STEP 2

After you’ve setup your location, keyboard, and language settings, up next is drive partitioning. You have few different options. Depending on free space on HDD and how many HDD’s you have you can setup 2 system on same HDD or each on separate drive. Linux based systems use GRUB loader to boot. If you install it alongside other OS on same drive Grub will replace default bootloader, adding both newly installed Linux OS and old system on boot list to choose which to boot into. For new users it is recommended to choose install alongside currently installed system. If you want to replace your OS with Ubuntu Budgie you can also choose that option. Something else option is for more advanced users. If you choose it be sure to make following mounting drives. / – which is root space where all software required for OS is stored. /home – partition used for most of the software you install and storing everyday files. /boot partition – where boot files will be stored. /swap – partition used for accessing and using hard disk space as additional memory when using near 99% of your RAM.

SIZES:

/ – 30GB or more
/swap – should be the same as your ram size – Note: Starting from 17.04 Ubuntu doesn’t use swap partition and instead uses swap files, so you don’t need to create swap partition.

/boot – 500MB
/home – rest of your hard disk space.

If you don’t choose manual partitioning, (something else option), installer will automatically partition your drive for installation. Each partition should be formated to ext4. To make them erase NTFS drive and then make 4 partitions with those mounting points. Swap partition needs to be set as swap partition type instead of ext4. Installer will ask you if you are sure before proceeding to installation. Note: If you have more than 2 HDD pay attention to where the bootloader is going to be installed since it could potentially mess your install. Next, choose username PC name and password. If you choose you can also encrypt your home partition for additional security.

Note: Make sure you’ve chosen additional media that contains codes so that you could play your media files right after installation. Sit back and relax, the installation will also download updates if you choose that option which could extend install time by few minutes depending on your Internet connection speed. When done, you can restart into newly installed Ubuntu Budgie.

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KStars Guide the feature-rich planetarium: KStar Tools, Imaging Planner Tool.

2026-09-17T08:32:00.000-05:00

The Imaging Planner tool assists users in selecting objects to image. Users can download catalogs of recommended objects, and may create and share their own catalogs. The tool calculates when objects in a catalog may be imaged on the selected night, given constraints such as minimum altitude, terrain, and moon elevation and separation. It can sort the objects along several dimensions including the number of hours an object may be imaged tonight (given the user’s geography, constraints and possibly artificial horizon), the object’s peak altitude, distance from the moon, constellation, name, and type. Objects can also be filtered out for several reasons (e.g., object type, whether it was previously imaged, keywords, whether the object has been selected, or if the user is uninterested). This tool aids object selection by displaying high-quality images, showing sky locations on the skymap, and providing links to follow to internet sites with more information and images. It allows attaching notes and links to objects, and selecting them for future consideration. This tool can be used with Ekos or other imaging tools, but does not directly interact with the imager; it helps the user decide what to image.

Setting up the Imaging Planner

The Imaging Planner tool can be used with KStars/Ekos or other astrophotography software. This section provides setup instructions, if you are new to KStars. Existing KStars users may find the initial steps unnecessary.
Download KStars

Follow the instructions at https://kstars.kde.org/download/.

Run KStars for the first time

The Startup Wizard appears when you run KStars for the first time. You can also access it from Settings → Startup Wizard.

Setup your geography in the Startup Wizard.

Click Download Extra Data.

If you are running KStars 3.7.6 or later, the only required Imaging Planner download is the Imaging Planner catalog (see image). It should say Catalog 2... or later.

If you are running earlier versions, it’s recommended to also download the NGC/IC, Open NGC, Abell, Sharpless, Hickson, and Lynds catalogs to greatly speed up the time it takes the Imaging Planner to start up for the first time.

In either case, you can also download any other catalogs you may want.
Setup your Artificial Horizon file (optional, but nice)
Your horizon file should be formatted as follows, where the lines starting with # are just comments and are optional, SideNearFence can be replaced by whatever you want to call your horizon, and the other lines have two floating point numbers for azimuth and altitude. This format is likely similar or identical to the horizon file format used by other imaging software:
# KStars Artificial Horizon export
#
Horizon SideNearFence
67.6236 22.7211
71.4942 21.7769
73.8178 20.6722
...
              
Go to Settings → Artificial Horizon. Click the icon that’s the 5th from the left (if you hover your mouse over it, and it should say “Import a previously exported horizon file”).

Navigate to your horizon file and select it.

Click Apply and then click Close.
Change your theme (Optional)

If you prefer a darker theme, go to Settings → Themes and select Black Body.

Running the planner for the first time

Go to Tools → Imaging Planner

The planner will start, but may prompt you to load a catalog

If you need a catalog or aren’t using the most recent catalog (e.g. the 770-object Catalog2) that was uploaded in the Download Extra Data section above, then find and click Load Catalog on the right side of the Imaging Planner.

It should bring up an Open file menu starting with a folder where you should be able to find Imaging Planner catalogs. Currently the latest catalog is in a folder called ImagingPlanner-catalog2.

Double click that folder, and it should bring you to a folder where you should be able to find all.csv.

Select (single click) all.csv and click Open. It should grey out the Imaging Planner, and start loading the catalog’s data. This load can take several minutes when first adding a catalog on KStars versions before 3.7.6. The delay should be much shorter on and after 3.7.6.

These long delays should only happen the first time you run the Imaging Planner tool. You will see a note near the top that keeps updating, saying things like 13/66 adding Arp 240.

If you have a catalog, or you’ve completed loading one, the Imaging Planner is ready for use.

Subsequent startups should be much faster, with your choices remembered.

Using the Imaging Planner

This video (created November 2024) demonstrates using the Imaging Planner tool: https://youtu.be/hrjqglLCW2s

The Object Table

The Object Table, which occupies most of the left side of the Imaging Planner tool, displays a list of objects from the loaded catalog, excluding any that have been filtered out (see the Filters section below). The table’s columns display various attributes. Select a row to see details, an altitude graph, and an image on the right.

The table sorts by imaging hours by default. Click a column header to sort by that column. Click again to reverse the sort order.

Right-clicking a row opens a menu of operations. Select multiple rows using “click then shift-click”. The right-click menu can operate on all selected rows, adding attributes to the objects. Choices are:

Pick the selected object (or un-pick an already picked object). Note you can select more than one object at a time with click then shift click. Marking an object as picked will allow you to later just display a few picked objects instead of the whole table. For example, one may spend time researching many objects, and when an interesting candidate is seen, it may be marked picked for later examination. After a while, when a collection of picked objects has been put together, one can only show the picked objects by using the picked filtering constraint (see Filters below).

Mark an object as already imaged (or undo that). Again, one can set this object attribute and later filter for not displaying these (or only displaying those).

Mark an object to be ignored (or undo that). Similar to marking as already imaged.

Center the object on the KStars SkyMap. This mostly makes sense if auto-centering is disable in the Options menu.

Screenshot. This is a more complex operation described in the screenshot sub-section below.

Objects that are marked as imaged are displayed with a different background color as the other images in order to distinguish them. This tool doesn’t automatically know that you’ve imaged an object, e.g. because you may have imaged it with KStars/Ekos. Rather you must explicitly mark an object as imaged using the menu, or use the Load Imaged button in the Filters section.

Objects that are picked are also displayed differently. They are shown in bold-italic and underlined in order to distinguish them.

The line above the table displays the number of rows in the table and total number of objects in the loaded catalog. They numbers may be different if some objects are filtered out. There is also a search box which will find a certain object if it is in the table.

Screenshots

You may want to place a nice finished example of a target you are considering on the SkyMap. This could be, for example, an image you admire on Astrobin. This could be useful to later help you frame your planned capture. One can do this using the image overlays capability. However, you can shortcut this procedure if all you want to do is create a temporary overlay (this session only). A demonstration video of this process can be found here and is summarized below:

Find a nice large example of the image you want to overlay and open up that web page so it’s visible on your screen.

Go back to the Imaging Planner tool and right click on the object in the object table. There select the bottom option Screenshot.

Your mouse cursor will change to the screenshot cursor. (You can use the Escape keyboard character if you want to cancel this operation.)

Using keyboard commands (not the mouse) navigate back to the nice image, move your mouse in the upper left corner of the image you wish to screenshot, press down and drag the mouse to the bottom right corner of that image, and then release the mouse. If you don’t know how to navigate to the image display with keyboard commands, you’d need to adjust the sizes of the nice image display and the imaging planner tool such that both fit on your screen unobstructed.

If all has gone well, a window will pop up with a Solve button. Click on Solve. This step can be automated by checking the Start Solving Immediately checkbox in the hamburger menu in the upper right corner of the main Imaging Planner window.

If the image was solved, the SkyMap should now be displayed with your example image placed correctly. You may need to zoom-in to see it if your view is zoomed out too far.

Date, Time and Geography

The date for which the analysis is done can be changed by the date input boxes at the top-right of the tool. One can be move back a day by clicking the button on the left of the date, and one can more ahead one day with the button to the right. One can change to an arbitrary date by selected the menu button by the date, or by simply editing the date text. The moon illumination for that day is displayed to the left of the date.

The time used (e.g. for the object’s position in the skymap) and the geography/location used to determine an object’s sky position are taken from the values being used in by KStars. To change your location, go to the Settings → Geographic menu. To change the current time, go to the Time → Set Time... menu.

Options and Help

There are two buttons to the right of the date control.

The options “hamburger” button brings up a small options menu. Currently the menu contains two checkboxes. One controls whether the system slews the KStars SkyMap to an object’s coordinates when the object is selected in the table. The second decides if the tool is an independent window (i.e. can go behind or in front of other KStars windows), or if it always goes in front of the main KStars window.

The 2nd button, when clicked, brings up this KStars Handbook in a web browser.

Object Information

The object information section near the top of the left-side of the tool displays information about the selected object. Click on an object and you should see this section filled in.

The top line should display the primary name, object type, and object size on the top line.

The 2nd line should display any alternate names the object has.

The 3rd line give transit and moon-separation information.

The last line allows you to add notes about the object. This information should be stored from session-to-session by KStars in its MySQL database, and is keyed by the object name. You edit these notes by clicking on the pencil icon at the left of the Note line. If you add a upto three URLs in the note (remember to use http or https at the start of the URL) then they should be automatically detected and an icon for browsing those URLs will be added to the Notes line. If the note you add is too long for the line allocated in the Object Information section, you can always see the full note by clicking the editing pencil button.

The Altitude Graph

The currently selected object’s altitude is graphed in the Altitude vs Time graph. The graph runs from just before sunset to just after sunrise. You’ll notice a dark background during the night. You may also notice a hash-pattern indicating moon illumination in the background. The altitude is graphed in white, but superimposed on top of it is a thicker green line indicating when the object can be imaged given your constraints (see Imaging Constraints section below). Thus if you just see a white altitude line, then the object cannot be imaged. If you see a green line, then those are the times and altitudes when the object can be imaged. If you click in the graph, you will see the altitude of the selected object displayed in the upper left of the graph.

In the above graph screenshot, the X axis corresponds to the nighttime between about 20:30 in the evening and 05:30 in the morning. The white line is a plot of the altitude of the selected object (which happened to be NGC 6384, not displayed). The superimposed bright green line shows it is imageable between a little after midnight until about 4:20am. The blue background on both sides of the graph correspond to just before and after astronomical twilight. The hashing shows some moonlight between sunset and almost 2:30am. The user clicked on the graph where (on the X axis) it was 10:18pm, and at that time the object’s altitude was 9.6º.

Imaging Constraints

The Imaging Planner tool calculates when during the night objects can be imaged. There are several constraints that affect this calculation. Some are set in this tool and a few are KStars/Ekos parameters that may need to be modified.

The minimum altitude in degrees that an object can be imaged is given in the Min alt box. If you change this value, you should see the Hours column recalculated in the object table and the graph recalculated in the Object Info section.

Similar to altitude, you can change the minimum Moon-separation angle in degrees.

If the artificial horizon checkbox is checked, then artificial horizon constraints are used to calculate the possible imaging times. The artificial horizon are the parts of the sky that are blocked from imaging by buildings or trees or the like at your telescope’s location. The artificial horizon is set up elsewhere in KStars (see Setting Menu and go down to Settings → Artificial Horizon) and at its simplest is a list of azimuth and altitude values. If you make use of this tool and image from an area where significant parts of the sky is blocked, it is recommended you set up and use the artificial horizon feature. Associated with the artificial horizon is the SkyMap’s terrain feature. If you set up your terrain image, then when the Imaging Planner tool displays the object on the SkyMap, you will see when it is relative to your local environment. Of course, you’d need to set a realistic imaging time–that is, if you plan during the daytime and the tool is locating objects at the current time, then the object may be set or behind buildings or trees.

KStars/Ekos uses astronomical twilight times to constrain imaging times. Using the defaults will result in no imaging outside of astronomical twilight times. If you wish to adjust this please see the constraint in the Ekos Scheduler's Offset menu–change the Dusk Offset positive to start imaging later, and negative to start imaging earlier. Similarly change Dawn Offset positive to continue imaging longer, and negative to stop imaging sooner. These controls can be found by selecting Tools → Ekos and then clicking on the Scheduler tab (2nd from the left), clicking the Options button on the bottom right, and the offset tab on the top-left.

Image/Object Search

The Search section provides some shortcuts for researching the currently selected object. The Wikipedia button brings up a browser window for Wikipedia using the object’s ID. Similar for Simbad. The NGC/IC button brings up a browser window for the Professor Seligman NGC/IC website.

The Astrobin button uses the Astrobin.com search facility to perform a slightly more detailed image search. You can cause it search for images in Astrobin with a certain image radius, and require that the result images have won “Astrobin awards” such as top-pick nomination, top-pick or image-of-the-day. Once you browse to the Astrobin website, you can, of course, modify the Astrobin search constraints as you like given the constraints and capabilities of the Astrobin website. The Astrobin search constraints can be hidden and exposed using the button on the left of the Search line.

Filters

There are a number of ways one can filter the objects displayed in the Imaging Planner’s object table. Filtering objects removes them from the table, but they can be accessed again by changing the filter. Note that the filter section can be hidden and exposed by clicking the small button at the left of the filter section.

Items can be filtered by how many hours they are image-able this night. Change the value in the Min Hours box, and objects with fewer hours than that value will not be displayed.

Checking or unchecking one of the object types will cause objects with those types to be displayed or not.

Picked: Checking Picked will cause only “picked” objects to be displayed. Similarly checking “Not Picked” will cause only objects not picked to be displayed. Checking Don't Care in the picked line will cause the picked-status to be irrelevant in whether an object is filtered from the table.

Similar to picked, Imaged causes objects labeled as previously imaged to be displayed or not.

Ignored causes objects labeled as “Ignored” to be displayed or not.

Keyword searches inside the Notes the user has added to the object, and is “true” if it sees a word in the note that matches the keyword (see the Object Information section above).

The Load Imaged button in the Imaged row of the Filters section allows you to load an already-imaged file. This file is a simple list of object names, one per row, that you can construct and load. Loading this will cause the tool to remember those object names and mark them as already imaged when it encounters them. If you wish to undo this action, the way to do that is to set the filters to just show imaged objects and then use the right-click/control-click menu to set the desired objects as not imaged. You can speed that up by selecting many objects at a time with the click then shift-click technique.

Object Image

If it is available, a small image of the currently selected object is displayed. Clicking on the image, astrophotographer credit line, or URL line will open a browser with given link to a full image, if a link was provided.

Note that the Load Catalog button is also in this section.

KStars setup for the Imaging Planner

There are a number of ways KStars could be setup to improve your experience with this tool.

The most important thing to do is go to Data → Download New Data... and download a catalog associated with this tool. The first time you use this tool you’ll need to click on the Load Catalog button and load the downloaded catalog. The tool should automatically download the catalog in subsequent runs.

Another important thing to do if you are running earlier versions of KStars (pre 3.7.6), also in the above Data → Download New Data... menu, is to download some deep-sky object catalogs. In particular the NGC IC, OpenNGC, Sharpless, Abell, Lynds and Hickson catalogs would be handy. You can run the Imaging Planner without these (small) downloads, but the start-up time on the first time you use this tool will be much longer if you don’t download them.

Read the Imaging Constraints section above and follow suggestions there, so that this tool can better predict how long an object can be imaged during the date selected.

Selected objects can be automatically centered in the SkyMap display. If that display is useful, you may want to adjust the zoom so that it is close to your imager’s field of view. The items below also apply to that SkyMap display.

You may also want to set the time in KStars to reflect when you’ll be imaging. See the Time menu.

If you don’t set the time, you may want to hide the terrain display (if you’ve set that up) and also not render the ground, as those may obscure the object. You show and hide the terrain display in the view menu, and the ground can be disabled in Settings → Guides with the Opaque Ground checkbox.

If you’re using a HiPS-based skymap, you would likely want local copies of the DSS data to speed-up the rendering of the SkyMap. See View → HiPS All Sky Survey and under there HiPS Settings... → Cache and enable the cache and enter the location of your local copy of the data. The data is available on https://irsa.ipac.caltech.edu/data/hips/CDS/DSS2/color/Norder1 … /Norder7 and another resource is https://coochey.net/?p=699

It would be useful to create a custom SkyMap “FOV Symbol” which is the same as the field-of-view of your imager. See Settings → FOV Symbols, and inside there select New → Camera, and enter the focal length of your optics and the camera’s specifications.

You may want to adjust the color theme, e.g. in Settings → Themes to Black Body if you like dark themes.

Catalogs

KStars currently provides a single imaging-planner catalog via the Data → Download New Data... menu item. The hope is that there will be future specialized catalogs, and possibly user-generated catalogs too. Therefore the catalog is formatted in a human-readable way.

Catalog Format

The format is currently a comma-separated file with one object on a row.

The first column is an object ID–which is the kind of ID that would work with the KStars Find Object tool.

The 2nd column is a filename (relative to the catalog’s location) where an approximate 300x300 jpeg image of the object can be found.

The 3rd column is the name of the image’s photographer.

The 4th is a link to a larger version of the image,

The 5th column is Creative Commons license permission for using the image (e.g. ACC is Attribution Creative Commons, ANCSACC is Attribution Non-Commercial ShareAlike Creative Commons, using the same conventions as the Astrobin.com website).

To add an object without an image, simply add the object ID with no following commas, or an object ID with 4 following commas, such as one of these lines (without quotes): “M 42”, or “M 42,,,,”. An example full line might be: “M 42,M_42.jpg,Hy Murveit,https://www.astrobin.com/x4dpey/,ACC”.

There are a few other possible specialized rows:

Rows that start with # are comments.

Rows that contain LoadCatalog RELATIVE_CATALOG_FILENAME mean that the contents of RELATIVE_CATALOG_FILENAME should be read in as if they were in this catalog file.

To add custom objects, create a .csv file (e.g., on your desktop). The first line should reference the existing catalog with LoadCatalog. Subsequent lines list your objects. Then, use Load Catalog on your new .csv file.

Loading Catalogs

Catalogs read in from Data → Download New Data... are stored in the standard KStars data directory, but catalogs can be read in from anywhere.

Use the Imaging Planner’s Load Catalog button to read in a new catalog.

When a catalog is read in, the previous catalog is discarded.

When the tool starts, it reads in the catalog last loaded in the previous session.

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Dolphin and other KDE apps will display the file creation date

2026-09-13T10:19:00.000-05:00

A feature traditionally requested in Linux and other Unix-like systems is the ability to see, in our file manager or other similar applications, the creation date of a given text document, image, audio, video, etc.

In Dolphin, we usually find the Modified column , to which we can also add the Accessed column and even the Created column (which for now still displays a pristine white).

That will change with the release of KDE Frameworks 5.58 in mid-May. It will no longer be necessary to use the terminal and search through inodes to access a file's creation date. The good old `stat` command :

[jose@replicante Documentos]$ stat archivo.ods

Fichero: archivo.ods

Tamaño: 10483 Bloques: 24 Bloque E/S: 4096 fichero regular

Dispositivo: 807h/2055d Nodo-i: 16815664 Enlaces: 1

Acceso: (0644/-rw-r--r--) Uid: ( 1000/ jose) Gid: ( 100/ users)

Acceso: 2019-04-15 10:41:16.516415434 +0200

Modificación: 2016-09-13 19:39:29.812419867 +0200

Cambio: 2017-02-14 00:44:56.470872122 +0100

Creación: 2016-08-09 14:44:44.989457790 +0200

Now that column will be full of information, thanks to the statx function (the evolution of stat, so to speak). It's currently compatible with current versions of glibc (>= 2.28), the C library from the GNU project that provides various APIs and system calls.

These capabilities, already implemented in the kernel (since Linux 4.11 ) and the most common file systems in GNU/Linux, such as ext4 and Btrfs , are now reaching the user's commonly used programs.

As a result, we will have an even more appealing KDE desktop , for both new and old users, capable of providing more complete and specific information.

You can find more information about this news and the week-by-week development of the KDE project on Nate Graham's blog . Interesting news that is also regularly covered by our friend Victorhck in the free world .

KStars Guide the feature-rich planetarium: KStar Tools, Observation Planner.

2026-09-10T08:31:00.000-05:00

Kristian Ivanov

Since KDE SC 4.4, Prakash Mohan’s GSoC work has been released in KStars. KStars now has an awesome observation planner to plan your observation sessions. The execute session option allows you to log information about objects as you observe them. Alternately, you may also write a short log in the session planner itself. We wish you a lot of fun planning your observations with KStars!

You can even add some pictures to the objects. The image list is a Google image search list. To add image to an object just press Find Image button on the right and then find an image that you like. If you do not have an Internet connection you can open an image from your hard drive. Note that images that will be used are going to be cropped to 600x600 pixels.

The first way of doing this is by pressing Ctrl+2 or Ctrl+L to open the Observation List, then press the Add Object button.

The Download all Images button does a search for the SDSS images and displays the DSS image if the requested RA/Dec is out of the SDSS footprint.

This is an SDSS image of a galaxy

This is an DSS image of the same galaxy

The Delete all Images button does the opposite. It deletes all downloaded images.

The image for the galaxy is now deleted

You can add more objects by pressing the Find Object button. It will open the Find Object tool which provides two accurate methods for sorting out the items, depending on what criteria you want to use. You can filter the list by objects type: Any, Stars, Solar System, Clusters (Globular and Open), Nebulae (Gaseous and Planetary), Galaxies, Comets, Asteroids, Constellations, Supernovae or Satellites. You can also filter the objects list by name. Enter the name of desired object in the Filter by name text box.

Inside Observation Planner window you can see the “Altitude vs Time” widget (AltvsTime), which shows you how the altitude of a selected object varies over time.

Below the AltvsTime widget, there is a text box in that you can add observing notes for current sky object.

Note that the Wish List is not the Session Plan. In the Wish List you can add objects that you wish to observe at some point. From there you can add them to the Session Plan.

You can see the pop-up window that comes after right-clicking on an object.

Add objects to Session Plan window

Here is the second way of adding objects in your Observation Plan, using the Observing List Wizard. You just need to press the fourth button on the top-left corner of the Observation Planner window.

Despite looking differently this way is basically the same as the first one. Although that it could be a bit more detailed. Here you can see the same categories of objects.

You can choose where these objects to be on the sky. There are four options available for you: All over the sky (which is the default option), by constellation and in a region (rectangular or circular).

You can choose the date for the observation and the place you are going to observe from.

You can choose the threshold of magnitude for the objects to be shown. In astronomy, absolute magnitude (also known as absolute visual magnitude when measured in the standard V photometric band) measures a celestial object’s intrinsic brightness.

You can save your observation plan. And it will save it with a .obslist extension.

You can also access the WUT (What’s up tonight), which could be of a great assistance to you. It can give you ideas what to observe on a date, time and place that you specify using the configuration buttons int the top-right corner of the What's up tonight window.

Another way of adding objects to your observation plan is using the newly introduced Batch Add will open up a text box where you can type many objects to add in one shot to the observation planner. Any objects not in the KStars database already will be resolved using SIMBAD Astronomical Database (provided this has been enabled in the Settings) and added to the database. The entire process of adding objects is slow and may take a while, and you can watch the progress in the Status Bar. Any objects that could not be found are then listed in an error message, so you can identify and fix the errors. Usually this may be because SIMBAD expects a different way of specifying the object (e.g. Sim 147 instead of Simeis 147). This new feature allows you to easily scrape data from observing lists on the web etc. and add them to your workflow in KStars.

This is how the Execution Session Window look. It can be opened by pressing Ctrl+2. In it you can also see some information about the selected object and you are able to add observing notes.

First Execute Session window

By pressing the Next Page button you will access the second page of Session Plan. Here you are able to see information not about your object, but about your equipment.

Second Execute Session window

Pressing the Next Target button will cause the Execute Session to open the first window about the next object.

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Add some life to your KDE launcher with the Ittu theme

2026-09-06T10:11:00.000-05:00

The login screen is where we quickly select a username and enter our password to access the desktop. There are multiple login managers in GNU/Linux, with SDDM ( Simple Desktop Display Manager ) being the one used by the KDE Plasma desktop environment.

These desktop environments can, in turn, have various "themes" with specific artwork. The official KDE theme is Breeze , but today we're going to try a new one called Ittu , which, in addition to having a slightly different layout by placing the buttons on the sides, introduces the possibility of having animated avatars for our users.

Its installation is very simple: go to system preferences or the application launcher and search for SDDM (Login Screen), then press the " Get New Login Screens " button, install the "Ittu" theme, select it and do the typical apply/accept.

By default, there are about 20 GIFs to use as avatars. If you prefer to use your own animations (200 x 200 pixels), you can copy them to the appropriate directory after downloading them. It would look something like this:

sudo cp 21.gif otro.gif /usr/share/sddm/themes/ittu/components/artwork/gifs

And then we choose the one we prefer for our avatars:

sudo cp 21.gif tannhausser.gif

(naturally, you replace my nickname with your username).

In the configuration file /usr/share/sddm/themes/ittu/theme.conf there is the possibility of introducing some customizations , relating to the background image , effects, transparencies , as well as the size or shape (square, circular) of the avatar.

Capturing an image of our login screen

You might want to share an image of your avatars, or of the login screen in question. Forget complicated scripts…most session managers offer a preview of themes, which we can invoke from the command line:

In the case of the Ittu Theme, it would be:

sddm-greeter --test-mode --theme /usr/share/sddm/themes/ittu

The same applies to Breeze or any other system we use with SDDM:

sddm-greeter --test-mode --theme /usr/share/sddm/themes/breeze

And take a screenshot of the pop-up window with our usual tool (Spectacle for example).

KStars Guide the feature-rich planetarium: KStar Tools, Solar System Viewer & Jupiter Moons Tool.

2026-09-03T08:28:00.000-05:00

This tool displays a model of our solar system as seen from above. The Sun is drawn as a yellow dot in the center of the plot, and the orbits of the planets are drawn as ellipses with the correct shapes and orientations. The current position of each planet along its orbit is drawn as a colored dot, along with a name label. The display can be zoomed in and out with the + and - keys, and the display can be recentered with the arrow keys, or by double-clicking anywhere in the window with the mouse. You can also center on a planet with the 0–9 keys (0 is the Sun; 9 is Pluto). If you center on a planet, it will be tracked as time passes in the tool.

The Solar System Viewer has its own clock, independent of the clock in the main KStars window. There is a timestep control widget here, similar to the one in the main window’s toolbar. However, this control defaults to a timestep of 1 day (so that the motions of the planets can be seen), and it starts out with the clock paused when the tool is opened. You may set the date to now by pressing the Today button.

Note

The current model used for Pluto’s orbit is only good for dates within about 100 years of the present date. If you let the Solar System clock advance beyond this range, you will see Pluto behave very strangely! We are aware of this issue, and will try to improve Pluto’s orbit model soon.

Jupiter Moons Tool

This tool displays the positions of Jupiter’s four largest moons (Io, Europa, Ganymede, and Callisto) relative to Jupiter, as a function of time. Time is plotted vertically; the units are days and “time=0.0” corresponds to the current simulation time. The horizontal axis displays the angular offset from Jupiter’s position, in arcminutes. The offset is measured along the direction of Jupiter’s equator. Each moon’s position as a function of time traces a sinusoidal path in the plot, as the moon orbits around Jupiter. Each track is assigned a different color to distinguish it from the others; the name labels at the top of the window indicate the color used by each moon (i.e. red for Io, yellow for Europa, green for Callisto and blue for Ganymede).

The plot can be manipulated with the keyboard. The time axis can be expanded or compressed using the + and - keys. The time displayed at the center of the window can be changed with the [ and ] keys.

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GitBook Guide: Create, Variables and expressions

2026-08-30T14:46:00.000-05:00

Variables and expressions

Create reusable variables that can be referenced in pages and spaces

With variables you can create reusable text that can be conditionally referenced in expressions and conditions for adaptive content.

If you repeat the same name, phrase or version number multiple times within your content, you can create a variable to help keep all those instances in sync and accurate — which is useful if you ever need to update them, or they’re complex and often mistyped.

You can create variables that are scoped to a single page, or a single space.

Create a new variable

To create a new variable, Click the Variables icon in the upper right corner when editing an open change request. This will open the Variables side panel.

You can use the toggle at the top to view and create variables scoped either to the current page you’re on, or all pages within the current space.

Clicking Create a variable will launch a modal where you can give your variable a name and a value.

Click Add variable to save your variable.

You can add variables to a single page or an entire space. When you update the value of a variable, every instance of it will update.

Variable names must start with a letter, and can contain letters, numbers and underscores.

Use variables in your content

Variables can be referenced and used within an expression — which you can insert into your content inline. After inserting an expression, double click it to open the expression editor.

Variables defined under your page are accessible under the page.vars object. Similarly, variables defined across your entire space are accessible under the space.vars object.

You can add variables to your content within expresions. The expression editor offers autocomplete options to help you find the variable you need.

Update a variable

You can update a variable at any point when within a change request. Updating its value will update the value across any expression blocks referencing it. The changed variable will go live to any published site once the change request is merged.

KStars Guide the feature-rich planetarium: Simulate Eyepiece View & The Script Builder Tool

2026-08-26T08:26:00.000-05:00

On the left hand side is the sky map shot from KStars. On the right hand side is the POSS (DSS) image of the same region. The orientation in the above example has been adjusted to match the view through a Dobsonian telescope at the location and time of the simulation in KStars.

This tool simulates how an object looks through your eyepiece. In addition to rendering the eyepiece field, KStars can also fetch and overlay the DSS imagery. Additionally, if you are using a Dobsonian telescope, you can rotate the field of view to match the eyepiece view.

To use this feature, first define your eyepieces’ fields of view using the FOV Symbol editor.

Then there are two ways to invoke the feature:

In Sky Map, right click on the desired object and click Simulate eyepiece view in the popup menu.

In observation planner, right click an object and click Simulate eyepiece view in the popup menu.

When the tool is first invoked, it will prompt a dialog to select the desired FOV to render the view. To compare the rendered view against a real sky image, click the Fetch DSS image button to download a DSS image. You can manually adjust the view to match your eyepiece using the rotation slider, the Invert view and Flip view check boxes. Alternatively, you can use a pre-calculated amount of rotation by using one item of the Preset: dropdown box that is tailored for different optical systems.

Arp84 eyepiece view with ticks enabled indicating how the chart must be oriented to match the eyepiece view through a Dobsonian at a given time (the generated data is for location McDonald Observatory Texas, and the date is 14th Dec 2016).

To export the view to a file, click Export button. Export enables adding ticks for printed charts as shown above and save the image.

The Script Builder Tool

KDE applications can be controlled externally from another program, from a console prompt, or from a shell script using the Inter-process communication protocol (D-Bus). KStars takes advantage of this feature to allow rather complex behaviors to be scripted and played back at any time. This can be used, for example, to create a classroom demo to illustrate an astronomical concept.

The problem with D-Bus scripts is, writing them is a bit like programming, and can seem a daunting task to those who do not have programming experience. The Script Builder Tool provides a GUI point-and-click interface for constructing KStars D-Bus scripts, making it very easy to create complex scripts.

Introduction to the Script Builder

Before explaining how to use the Script Builder, I provide a very brief introduction to all of the GUI components; for more information, use the “What’s This?” function.

The Script Builder is shown in the above screenshot. The box on the left is the Current Script box; it shows the list of commands that comprise the current working script. The box on the right is the Function Browser; it displays the list of all available script functions. Below the Function Browser, there is a small panel which will display short documentation about the script function highlighted in the Function Browser. The panel below the Current Script box is the Function Arguments panel; when a function is highlighted in the Current Script box, this panel will contain items for specifying values for any arguments that the highlighted function requires.

Along the top of the window, there is a row of buttons which operate on the script as a whole. From left to right, they are: New Script, Open Script..., Save Script, Save Script As..., and Test Script. The function of these buttons should be obvious, except perhaps the last button. Pressing Test Script will attempt to run the current script in the main KStars window. You should move the Script Builder window out of the way before pressing this, so you can see the results.

In the center of the window, there is a column of buttons which operate on individual script functions. From top to bottom, they are: Add Function, Remove Function, Copy Function, Move Up, and Move Down. Add Function adds the currently-highlighted function in the Function Browser to the Current Script box (you can also add a function by double-clicking on it). The rest of the buttons operate on the function highlighted in the Current Script box, either removing it, duplicating it, or changing its position in the current script.

Using the Script Builder

In order to illustrate using the Script Builder, we present a small tutorial example where we make a script that tracks the Moon while the clock runs at an accelerated rate.

If we are going to track the Moon, we will need to point the display at it first. The lookToward function is used to do this. Highlight this function in the Function Browser, and note the documentation displayed in the panel below the Browser. Press the Add Function button to add this function to the Current Script box. The Function Arguments panel will now contain a combobox labeled “Dir”, short for direction. This is the direction in which the display should be pointed. The combobox contains only the cardinal compass points, not the Moon or any other objects. You can either enter “Moon” in the box manually, or press the Object... button to use the Find Object... window to select the Moon from the list of named objects. Note that, as usual, centering on an object automatically engages object-tracking mode, so there is no need to add the setTracking function after lookToward.

Now that we have taken care of pointing at the Moon, we next want to make time pass at an accelerated rate. Use the setClockScale function for this. Add it to the script by double-clicking on it in the Function Browser. The Function Arguments panel contains a timestep spinbox for setting the desired time step for the simulation clock. Change the timestep to 3 hours.

OK, we have pointed at the Moon and accelerated the clock. Now we just want the script to wait for several seconds while the display tracks on the Moon. Add the waitFor function to the script, and use the Function Arguments panel to specify that it should wait for 20 seconds before continuing.

To finish up, let us reset the clock’s timestep to the normal value of 1 second. Add another instance of setClockScale, and set its value to 1 sec.

Actually, we are not quite done yet. We should probably make sure that the display is using Equatorial coordinates before the script tracks the Moon with an accelerated time step. Otherwise, if the display is using Horizontal coordinates, it will rotate very quickly through large angles as the Moon rises and sets. This can be very confusing, and is avoided by setting the View Option UseAltAz to “false”. To change any View Option, use the changeViewOption function. Add this function to the script, and examine the Function Arguments panel. There is a combobox which contains the list of all options which can be adjusted by changeViewOption. Since we know we want the UseAltAz option, we could simply select it from the combobox. However, the list is quite long, and there is no explanation of what each item is for. It therefore may be easier to press the Browse Tree... button, which will open a window containing a tree view of the available options, organized by topic. In addition, each item has a short explanation of what the option does, and the data type of the option’s value. We find UseAltAz under the Skymap Options category. Just highlight this item and press OK, and it will be selected in the combobox of the Function Arguments panel. Finally, make its value “false” or “0”.

One more step: changing UseAltAz at the end of the script does us no good; we need this to be changed before anything else happens. So, make sure this function is highlighted in the Current Script box, and press the Move Up button until it is the first function.

Now that we have finished the script, we should save it to disk. Press the Save Script button. This will first open a window in which you can provide a name for the script, and fill in your name as the author. Enter “Tracking the Moon” for a name, and your name as the author, and press OK. Next, you will see the standard KDE Save File dialog. Specify a filename for the script and press OK to save the script. Note that if your filename does not end with “.kstars”, this suffix will be automatically attached. If you are curious, you can examine the script file with any text editor.

Now that we have a completed script, we can run it in a couple of ways. From a console prompt, you can simply execute the script as long as an instance of KStars is currently running. Alternatively, you can execute the script from within KStars using the File → Run Script... menu item.

source

GitBook Guide: Create, blocks

2026-08-23T15:38:00.000-05:00

Add and edit blocks within your content

GitBook is a block-based editor, meaning you can add different kinds of blocks to your content — from standard text and images to interactive blocks. Your pages can include any combination of blocks you want, and there’s no limit to the number of blocks you can have on a page.

GitBook's built in content blocks.

Inserting a new content block

You can insert a new content block below an existing block using your mouse:

Hover over the block above the place you need the new content block.
Click on the + icon that appears on the left to open the insert palette.
Select the block you want from the drop-down menu to insert it.

Alternatively, on a new line, you can press / to launch the insert palette, which lists all the available blocks. You can scroll through the list to find the one you want, or use your keyboard to search for the block you want, navigate up and down the list, and insert it with Enter.

Exiting a block

Some content blocks capture the editing cursor to allow you to add content in the context of that block. For example, when you’re writing in a hint block, hitting Enter will add a new line within the hint block, rather than a new paragraph below.

When you are done, you can continue adding new content to the page either by inserting a new block using the + button to the left of your content, or by hitting ⌘ + Enter on a Mac or Ctrl + Enter on a PC.

Selecting blocks and interacting with selected blocks

You can select a single block by pressing the Esc key with the cursor in the block. You can also select multiple blocks by highlighting content within them and hitting Esc.

Once selected, you can:

Select more blocks by clicking on them while keeping the Shift ⇧ key pressed.
Moving up and down to select the block above or below, using the ↑ and ↓ keys
Copy the entire block using ⌘ + C (Mac) or Ctrl + C (Windows)
Cut the entire block using ⌘ + X (Mac) or Ctrl + X (Windows)
Delete the selected block or blocks using ⌫ or Del.

Full-width blocks

By making your blocks full width, you can create a clear visual hierarchy in your content, or simply give more space to content that needs it.

To make a block full width, click on the Options menu next to your block and select Full width. This feature is available for the following block types:

Code
Images
Tables
Cards
Columns
Integration blocks

Some blocks will always display full-width, regardless of the page’s width setting in the the Page options menu:

KStars Guide the feature-rich planetarium: KStars Tools, Altitude vs. Time Tool & What’s up Tonight? Tool.

2026-08-19T08:24:00.000-05:00

This tool plots the altitude of any objects as a function of time, for any date and location on Earth. The top section is a graphical plot of altitude angle on the vertical axis, and time on the horizontal axis. The time is shown both as standard local time along the bottom, and sidereal time along the top. The bottom half of the graph is shaded green to indicate that points in this region are below the horizon.

There are a few ways to add curves to the plot. The simplest way to add the curve of an existing object is to simply type its name in the Name: input field, and press Enter, or the Plot button. If the text you enter is found in the object database, the object’s curve is added to the graph. You can also press the Find Object... button to open the Find Object Window to select an object from the list of known objects. If you want to add a point that does not exist in the object database, simply enter a name for the point, and then fill in the coordinates in the RA: and Dec: input fields. Then press the Plot button to add the curve for your custom object to the plot (note that you have to pick a name that does not already exist in the object database for this to work).

When you add an object to the plot, its altitude vs. time curve is plotted with a thick white line, and its name is added to the listbox at the lower right. Any objects that were already present are plotted with a thinner red curve. You can choose which object is plotted with the thick white curve by highlighting its name in the listbox.

These curves show the objects’ Altitude (angle above the horizon) as a function of time. When a curve passes from the lower half to the upper half, the object has risen; when it falls back to the lower half, it has set. For example, in the screenshot, the minor planet Quaoar is setting at around 15:00 local time, and is rising at about 04:00 local time.

The plot can be easily zoomed and panned using the mouse. The zooming level can be adjusted using the mouse scroll wheel. When the plot is zoomed out, the zooming level will be automatically limited to a default minimum value, such as the axes’ ranges are able to cover the entire plot (i.e. on vertical axis, the maximum altitude value should touch the top edge of the plot frame). The same principle is applied when the plot is panned using the mouse movement. For panning the plot, all you need to do is to click on the point of the plot you want to pan and then drag the mouse on your desired direction: left, right, up or down.

Another useful feature that Altvstime tool provides is its ability to compute and mark the Rise/Set/Transit times. This can be accomplished by a simple press of one of the Rise, Set or Transit buttons. When one of these buttons is pressed, a filled colored circle will be marked on the curve. The color used for Rise, Set and Transit dots are: red for Rise, blue for Set and green for Transit time. For a more intuitive way of using these buttons, they are marked with the color of their specific dots. This way, the user can easily understand the plot and make the association between a certain color and its significance.

Altvstime tool provides an easy way to find out the altitude of a sky-object at a certain moment of time using the Compute button. After you select the object from the Objects list and set the moment of time, the altitude can be computed by pressing the Compute button. But this is not the only way you can find out the altitude. Another method is to hover with mouse above one curve and thus, a tooltip containing the Local Time, Local Sidereal Time and Altitude will come up. This way, you can read the information in real time.

The Altitude of an object depends on both where you are on Earth, and on the Date. By default, the Tool adopts the Location and Date from the current KStars settings. You can change these parameters in the Date & Location Tab. To change the Location, you can press the Choose City... button to open the Set Geographic Location Window, or enter Longitude and Latitude values manually in the input fields, and press the Update button. To change the Date, use the spin and combo boxes, then press Update. Note that any curves you had already plotted will be automatically updated when you change the Date and/or Location.

Tip

Exercise:

Plot the Sun’s Altitude curve. Make sure the geographic location is not near the equator. Change the Date to some time in June, and then again to sometime in January. You can see easily why we have seasons; in the winter, the Sun is above the horizon for less time (the days are shorter), and its altitude is never very high.

The “What’s up Tonight?” (WUT) tool displays a list of objects that will be visible at night from any location, on any date. By default, the Date and Location are taken from the current settings in the main window, but you can change either value using the Change Date... and Change Location... buttons at the top of the WUT window.

The WUT tool also displays a short almanac of data for the selected date: the rise and set times for the Sun and moon, the duration of the night, and the Moon’s illumination fraction.

Below the almanac is where the object information is displayed. The objects are organized into type categories. Select an object type in the box labeled Select a category:, and all objects of that type which are above the horizon on the selected night will be displayed in the box labeled Matching objects:. For example, in the screenshot, the Planets category has been selected, and three planets which are up on the selected night are displayed (Mars, Jupiter and Saturn). When an object in the list is selected, its rise, set and transit times are displayed in the lower-right panel (i.e. Mars rises at 17:13, transits at 21:46 and sets at 02:16). In addition, you can press the Object Details... button to open the Object Details window for that object.

By default, the WUT will display objects which are above the horizon between sunset and midnight (i.e. “in the evening”). You can choose to show objects which are up between midnight and dawn (“in the morning”), or between dusk and dawn (“any time tonight”) using the combobox near the top of the window. You can also choose to see only those objects that are brighter than a magnitude by setting a minimum magnitude using the Show objects brighter than magnitude: spinbox. You may center the selected object in the Sky Map or add it to Wish List by pressing the Center Object or Add to List button.

source

Does Ubuntu have blockchain applications?

2026-08-16T11:51:00.000-05:00

Ubuntu is widely used for blockchain applications. It provides a stable, open-source environment for running blockchain nodes, developing decentralized apps (dApps), and building Web3 solutions. Developers often choose Ubuntu because of its security, flexibility, and strong support for open-source tools.

How Ubuntu Supports Blockchain Applications

Web3 Development Environment Ubuntu is a popular choice for setting up Web3 tools like Node.js, npm, and Truffle Suite for Ethereum smart contract development.
Blockchain Node Hosting Guides exist for running nodes of major blockchains such as Ethereum, Polkadot, and Cosmos on Ubuntu 24.04. This allows developers and enterprises to participate directly in blockchain networks.
Open-Source Synergy Linux (and Ubuntu in particular) aligns with blockchain’s philosophy of decentralization, transparency, and security. Its stability and flexibility make it ideal for running dApps, cryptocurrency wallets, and blockchain infrastructure.

⚙️ Examples of Blockchain Applications on Ubuntu

Application Type
Example Tools/Platforms
Why Ubuntu Works Well

Smart Contract Development
Truffle, Hardhat, Solidity
Easy setup with Node.js and npm

Blockchain Nodes
Ethereum, Polkadot, Cosmos
Secure, stable server environment

dApp Hosting
IPFS, Web3.js, Metamask integration
Open-source ecosystem support

Crypto Wallets
Bitcoin Core, Electrum
Strong security and package management

Enterprise Blockchain
Hyperledger Fabric, Corda
Ubuntu’s server-grade reliability

Sources:

⚠️ Considerations & Challenges

Hardware Requirements: Running full blockchain nodes (e.g., Ethereum) can be resource-intensive. Ubuntu supports this but requires sufficient CPU, RAM, and storage.
Security: While Ubuntu is secure, blockchain applications demand constant updates and monitoring to prevent vulnerabilities.
Learning Curve: Developers new to Linux may need time to adapt to command-line tools and package management.

In short, Ubuntu doesn’t just “have” blockchain applications — it’s one of the most common operating systems used to build and run them. If you’re interested, I can walk you through setting up a basic Ethereum development environment on Ubuntu or compare node requirements for different blockchains.

KStars Guide the feature-rich planetarium: KStars Tools, Object Details Window, The Astrocalculator.

2026-08-12T08:22:00.000-05:00

Object Details Window

The Object Details Window presents advanced data available about a specific object in the sky. To access this tool, right-click on any object, and select the Details... item from the popup menu.

The window is divided into a number of tabs. In the General tab, we present basic data about the current object. This includes names and catalog designations, object type, and magnitude (brightness). On the Position tab are the object’s Equatorial and Horizontal coordinates, as well as its rise, set and transit times.

In the Links tab, you can manage the internet links associated with this object. The Image and Information links associated with the object are listed. These are the links that appear in the popup menu when the object is right-clicked. You can add custom links to the object with the Add Link... button. This will open a window in which you fill in the URL and link text for the new link (you can also test the URL in the web browser from this window). Every time you add a custom URL to a certain object, you are able to choose the resource type using the Resource Type button. Keep in mind that the custom link can easily point to a file on your local disk, so you can use this feature to index your personal astronomical images or observing logs.

You can also modify or remove any link using the Edit Link... and Remove Link... buttons.

The Advanced tab (not available for all objects) allows you to query professional astronomical databases on the internet for information regarding the current object. To use these databases, double click on the desired database in the list to see the results of your query in a web browser window. The query is made using the primary name of the object you clicked on to open the Details Dialog. The following databases are available for querying:

Set of Identifications, Measurements, and Bibliography for Astronomical Data (SIMBAD): SIMBAD is similar to NED, except it provides data about all kinds of objects, not just galaxies.

SkyView: Provides images from All-Sky surveys that have been performed in dozens of different parts of the spectrum, from Gamma Rays to the Radio. The KStars interface will retrieve an image from any of these surveys, centered on the selected object.

High Energy Astrophysical Archive (HEASARC): Here you can retrieve data about the current object from a number of “High-energy” observatories, which covers the Ultraviolet, X-ray and Gamma Ray portions of the electromagnetic spectrum.

NASA/IPAC Extragalactic Database (NED): NED provides encapsulated data and bibliographic links about extragalactic objects. You should only use NED if your target is extragalactic; i.e. if it is itself a galaxy.

NASA Astrophysical Data System (ADS): This incredible bibliographic database encompass the entire body of literature published in international peer-review Journals about astronomy and astrophysics. The database is divided into four general subject areas (Astronomy and Astrophysics, Astrophysics Preprints, Instrumentation, and Physics and Geophysics). Each of these has three sub-nodes that query the database in different ways. “Keyword search” will return articles which listed the object’s name as a keyword. “Title word search” will return articles which included the object name in their Title, and the “Title & Keyword search” uses both options together.

Multimission Archive at Space Telescope (MAST): The Space Telescope Science Institute provides access to the entire collection of images and spectra taken with the Hubble Space Telescope, as well as several other space-based observatories.

Finally, in the Log tab, you can type in some text that will remain associated with this object’s Details window. You could use this to attach personal observing notes, for example. Your notes will be saved, such that you can easily read or use them next time when you will use KStars.

The KStars Astrocalculator provides several modules that give you direct access to algorithms used by the program. The modules are organized by subject:

Time Calculators

Julian Day

Sidereal Time

Almanac

Equinoxes and Solstices

Coordinate Converters

Equatorial/Galactic Coordinates

Apparent Coordinates

Horizontal Coordinates

Ecliptic Coordinates

Angular Distance

Geodetic Coordinates

Solar System

Planets Coordinates

Julian Day module

This module converts between the calendar Date and time:, the Julian day:, and the Modified julian day:. The Modified Julian Day is simply equal to the Julian Day - 2,400,000.5.

To use the module, enter one of the three dates and the corresponding values for the other two date systems will be displayed. You can also set the Date and time to now, by pressing the Now button.

There is a batch mode for this module. To use it, simply generate an input file whose lines each contain a number of values for the input parameter: “Date and time”, “Julian day” or “Modified Julian day”. Then specify the input and output filenames, and press the Compute button to generate the output file. The output file will contains values for the other two complementary parameters. For example, if your input file contains a set of Date and time: values, then each line of the output file will contain values for Julian day: and Modified julian day:. You can read the output directly in KStars by pressing the View output... button.

Tip

Exercise:

What calendar date does MJD = 0.0 correspond to?

Sidereal Time module

This module converts between Universal Time and Local Sidereal Time. First, select a geographic location and a date for the calculation. Then the corresponding value for the other Time will be displayed.

There is a batch mode for this module. To use it, simply generate an input file whose lines each contain values for the input parameter: Compute sidereal time or Compute standard time from to left dropdown box. You can choose to set the Date: and Location: in the current window, or you can tell KStars to read these values from the Input file:. Then specify the input and output filenames, and press the Compute button to generate the output file. The output file will contains values for the complementary parameter. For example, if your input file contains a set of “standard time” values, then each line of the output file will contain values for “sidereal time”. You can read the output directly in KStars by pressing the View output... button.

Day Duration module

This module computes the length of day as well as sunrise, sun-transit (noon), and sunset times for any calendar date, for any location on Earth. First select the desired geographic coordinates and date, then the data is computed and displayed.

Equinoxes and Solstices module

The Equinoxes and Solstices module calculates the date and time of an equinox or solstice for a given year. You specify the year and the date and time of the events (Vernal Equinox, Summer Solstice, Autumnal Equinox, or Winter Solstice) are displayed.

There is a batch mode for this module. To use it, simply generate an input file whose lines each contain a year for which the Equinox and Solstice data will be computed. Then specify the input and output filenames, and press the Compute button to generate the output file. Each line in the output file contains the input year and the date of each event. You can also read the output directly in KStars by pressing the View output... button.

Equatorial/Galactic Coordinates module

This module converts from Equatorial coordinates to Galactic coordinates, and vice versa. Fill in the coordinate values in either the Galactic coordinates or Equatorial coordinates (J2000) section. Alternatively set the equatorial coordinates by selecting an object using the Find Object dialog. Then the complementary coordinates will be filled in.

The module contains a batch mode for converting several coordinate pairs at once. You must construct an input file in which each line contains two values: the input coordinate pairs (either Equatorial or Galactic). Then specify which coordinates you are using as input, and identify the input and output filenames. Finally, press the Run button to generate the output file, which will contain the converted coordinates (Equatorial or Galactic; the complement of what you chose as the input values).

Apparent Coordinates module

The Apparent Coordinates module converts the catalog coordinates of a point in the sky to its apparent coordinates for any date. The coordinates of objects in the sky are not fixed, because of precession, nutation and aberration. This module takes these effects into account.

To use the module, first enter the desired target date and time in the Target Time & Date section. Then, enter the catalog coordinates in the Catalog Coordinates section. Alternatively you can set the catalog coordinates by selecting an object using the Find Object dialog. You can also specify the catalog’s epoch here (usually 2000.0 for modern object catalogs). Then the object’s coordinates for the target date will be displayed in the Apparent coordinates: section.

Horizontal Coordinates module

This module converts from Equatorial coordinates to Horizontal coordinates. First, select the date, time, and geographic coordinates for the calculation. Then, fill in the equatorial coordinates to be converted or use the Find Object dialog in the Equatorial Coordinates (J2000) section. The corresponding Horizontal coordinates will be presented in the Horizontal Coordinates section.

Ecliptic Coordinates module

This module converts between Equatorial coordinates and Ecliptic coordinates. First, select Date and time:. Then, fill in the coordinate values in either the Ecliptic Coordinates or Equatorial Coordinates section. Alternatively set the equatorial coordinates by selecting an object using the Find Object dialog. Then the complementary coordinates will be filled in.

Angular Distance module

The Angular Distance tool is used to measure the angle between any two points on the sky. You simply specify the Equatorial coordinates of the desired pair of points, and then obtain the angle between the two points.

There is also a Batch mode for this module. In batch mode, you specify an input filename which contains a number of parameters (up to four) on each line: the initial right ascension (RA), initial declination (Dec), final right ascension and final declination. By default, each line should contain four numbers signifying the RA and Dec values for pairs of points. Alternatively, you can specify a single value for any of these four coordinates in the calculator panel (the corresponding values in the input file should be skipped if they are specified in the calculator).

Once you have specified the input filename and an output filename, simply press the Run button to generate the output file.

Geodetic Coordinates module

The normal geographic coordinate system assumes that the Earth is a perfect sphere. This is nearly true, so for most purposes geographic coordinates are fine. If very high precision is required, then we must take the true shape of the Earth into account. The Earth is an ellipsoid; the distance around the equator is about 0.3% longer than a Great Circle that passes through the poles. The Geodetic Coordinate system takes this ellipsoidal shape into account, and expresses the position on the Earth’s surface in Cartesian coordinates (X, Y and Z) or in Geographic coordinates (Longitude, Latitude and Elevation).

To use the module, first select which coordinates you will use as input in the Select Input Coordinates section: Cartesian or Geographic radio buttons. Then select an ellipsoid model and fill in the input coordinates in either the Cartesian Coordinates section or the Geographic Coordinates section. When you press the Convert button, the corresponding coordinates will be filled in.

The module contains a batch mode for converting several coordinate values at once. You must construct an input file in which each line contains up to three numbers: the input coordinate values (either Cartesian or Geographic). Then specify which coordinates you are using as input, and identify the input and output filenames. Finally, press the Run button to generate the output file, which will contain the converted coordinates (Cartesian or Geographic; the complement of what you chose as the input values).

Planet Coordinates module

The Planet Coordinates module computes positional data for any major solar system body, for any time and date and any geographic location. Simply select from the Solar system body: drop-down list, and specify the desired date, time, and geographic coordinates (these values are preset to the current KStars settings). Then the Equatorial, Horizontal, and Ecliptic coordinates of the body are computed and displayed.

There is a batch mode for this module. You must construct an input file in which each line specifies values for the input parameters (solar system body, date, time, longitude, and latitude). You may choose to specify a constant value for some of the parameters in the calculator window (these parameters should be skipped in the input file). You may also specify which of the output parameters (Equatorial, Horizontal, Heliocentric ecliptic and Geocentric ecliptic coordinates) should be calculated. Finally, specify the input and output filenames, and press the Run button to generate the output file with the computed values.

source

The best Office applications for Ubuntu

2026-08-09T11:48:00.000-05:00

The best office applications for Ubuntu are LibreOffice, OnlyOffice, WPS Office, Calligra Suite, and Apache OpenOffice. These suites cover word processing, spreadsheets, and presentations, with LibreOffice being the most popular and OnlyOffice offering excellent Microsoft Office compatibility.

️ Top Office Suites for Ubuntu

Office Suite
Key Features
Pros
Cons
Best For

LibreOffice
Writer, Calc, Impress, Draw, Base, Math
Free, open-source, strong community, wide format support
Interface feels dated, occasional MS Office formatting issues
General users, open-source enthusiasts

OnlyOffice
Docs, Sheets, Slides
Modern UI, excellent MS Office compatibility, collaborative editing
Heavier resource usage, fewer advanced features
Teams needing collaboration & MS Office-like experience

WPS Office
Writer, Spreadsheets, Presentation
Sleek UI, strong MS Office compatibility, PDF tools
Free version has ads, closed-source
Users who want a polished MS Office-like feel

Calligra Suite
Words, Sheets, Stage, Flow, Kexi
KDE integration, creative tools (mind maps, flowcharts)
Less popular, weaker MS Office compatibility
KDE users, creative professionals

Apache OpenOffice
Writer, Calc, Impress, Draw, Base
Stable, long history, free
Slower updates, weaker MS Office compatibility than LibreOffice
Users who want a simple, stable suite

Sources:

Key Considerations

Compatibility with Microsoft Office: If you frequently exchange files with MS Office users, OnlyOffice or WPS Office are better choices.
Open-source vs Proprietary: LibreOffice and Calligra are fully open-source, while WPS Office is proprietary.
Collaboration Needs: OnlyOffice shines with real-time collaboration, similar to Google Docs.
System Resources: LibreOffice is lighter, while OnlyOffice and WPS Office may demand more RAM/CPU.

⚠️ Limitations & Trade-offs

Formatting Issues: Even the best alternatives sometimes struggle with complex MS Office documents (especially macros or advanced Excel formulas).
Updates: Apache OpenOffice is less actively maintained compared to LibreOffice, which receives frequent updates.
Privacy Concerns: Proprietary suites like WPS Office may raise concerns for users who prefer open-source transparency.

If you want the most reliable and widely used option, go with LibreOffice. If MS Office compatibility is critical, choose OnlyOffice. For a sleek, modern UI, WPS Office is a strong contender.

KStars Guide the feature-rich planetarium: FITS Viewer Embedded FITS Viewer & 3D Star Profile & Data Visualization Tool

2026-08-05T08:19:00.000-05:00

In Ekos Focus, Guide, and Align modules, captured images are displayed in the embedded FITS Viewer. The embedded viewer includes a floating bar that can be used to perform several functions:

Zoom Out

Zoom In

Default Zoom

Zoom To Fit

Toggle Cross Hairs

Toggle Pixel Gridlines

Toggle Detected Stars: Highlight detected stars with red circles.

Star Profile: View detailed 3D star profile.

The floating bar is automatically hidden once the mouse leaves the embedded viewer area. You can use the mouse to pan and zoom just like the standalone FITS Viewer. The green tracking box can be used to select a specific star or region within the image, for example, to select a guide star.

3D Star Profile & Data Visualization Tool

The 3D data visualization tool can plot 3D graphs of the selected region of the image. This is particularly useful for astrophotographers who want to visualize the profile of a star they are considering focusing or guiding on. For scientists, it enables them to examine a cross-section of the data to understand the relative brightness of different objects in the image. Additionally, it empowers imagers who want to visually see what is going on in their data collection in a new way.

To use the new feature, the user needs to select the View Star Profile icon in one of the Ekos Module Views, or in the FITS Viewer. Then, the region selected in the green tracking box will show up in the 3D graph as shown above. The user will then have one of the following toolbars at the bottom.

At the far left, the sample size combo box will let the user select the size of the image crop shown in the graph. This option is only available in the Summary Screen, the Align Module, and the FITS Viewer. The second combo box lets the user control whether they are selecting an individual item, or a row, or a column of pixels. The slice button will be enabled if the user selects Row or Column. It will put the graph in slice mode so that the user can see a cross-section view of the image. Third, is a checkbox that will open up two sliders that will let the user drag the slider to change the selection. This is extremely useful in the slide mode to change the selected point and to move the cross section around the graph. It is also useful in the normal view when in Explore Mode so that the user can zoom around the image examining the pixels.

Then the user has the Zoom To combo box, which the user can use to zoom the graph to different preset locations. Next is the combo box that lets the user select the color scheme of the graph. Then are the HFR and the Peak checkboxes, which will both turn on the HFR and Peak labels on each found star in the image, but will also display one of them at the bottom of the screen. And finally comes the Scaling checkbox, which enables the Scaling Side Panel. There are three sliders in that panel, one to control the minimum value displayed on the graph or “black point”, one to control the maximum value displayed in the graph or the “white point”, and a third that is disabled by default that lets the user control the cutoff value for data displayed on the graph.

This third slider is very useful to get really big peaks out of the way so you can study the finer details in the image. There is a checkbox at the top to enable/disable the cutoff slider. And finally at the bottom of the sliders is the Auto scale button. This will auto scale the sliders as you sample different areas in the image. It will not only optimize the display of the data but will also affect the minimum and maximum points of the slider. If you disable auto scale, then as you sample different parts of the image, they will be displayed at the same scale. A particularly useful way to use this is to select an area of your image using auto scale, tweak the min, max, and cutoff sliders to your liking, and then turn off the auto scale feature to explore other areas of the graph.

source

GitBook Guide: Create, Content structure

2026-08-02T17:19:00.000-05:00

The structure of your content in GitBook is organized through pages, spaces and collections. Pages live inside of spaces, and collections are groups of spaces.

Spaces

Create a space to organize your documentation in one place.

Pages

Create pages to split up and edit the content in your documentation.

Collections

Create collections to group spaces together.

Spaces

Organize the content you create and publish into spaces

A space is a project that lets you work on a collection of related pages. They allow you to write content, organize pages, add integrations and more.

Create a space

Click the + button next to the Spaces header in the sidebar and choose New space to create a new space. You can also create a new space inside a collection.

You can edit a space’s name by hovering over the name in the space header.

Duplicate a space

To duplicate a space, open that space's Action menu in the sidebar and select Duplicate.

Duplicating a space will create a copy of the source space, in the same location (organization, collection, sub-collection, etc.).

Move a space

You can move a space by opening the space’s Action menu in the sidebar, selecting Move space to… and choosing a destination. Alternatively, you can drag and drop spaces in the sidebar to move or reorder them. You can move spaces between collections within the same organization, as long as you have an admin role.

Delete a space

You can delete a space by opening the space’s Action menu in the sidebar and selecting Delete.

Deleted spaces can be restored from the Trash for up to 7 days. After this, they will be permanently deleted.

KStars Guide the feature-rich planetarium: FITS Viewer Features, FITS Viewer Solver & FITS Viewer Live Stacker.

2026-07-30T08:17:00.000-05:00

Displays multi-channel FITS histogram. The user can rescale the image by optionally defining an upper and lower limit for the cutoff region. The rescaling operation (linear, logarithmic, or square-root) may then be applied to the region enclosed by the upper and lower limits.

FITS Header

Displays a read-only table listing FITS header keywords and values.

Statistics

Provides simple statistics for minimum and maximum pixel values and their respective locations. FITS depth, dimension, mean, and standard deviation.

FITS Viewer Solver

The FITS Viewer Solver is used to plate-solve the image loaded in the FITS Viewer’s tab. It only works with the internal StellarSolver. You get the RA and DEC coordinates for the center of the image, the image’s scale, the angle of rotation, and the number of stars detected in the image. Its main use case is debugging plate-solving issues in Ekos, though the information displayed can be generally useful. The controls and displays are described below.

Solve Button. Pressing this button starts plate solving. When the system is plate solving, the button becomes an abort button.

Scale: Checking the Use Scale checkbox constrains the solver to use approximately the pixel or image scale given. The scale is entered in the box and the units for the scale can be chosen from image width in degrees, image width in arc-minutes, and arc-seconds per pixel. When a solve successfully completes, it replaces the value in the box with solution’s scale.

Position: Checking the Use Position checkbox constrains the solver to search near the RA and DEC coordinates given. The extent of the search is given by the user in the Radius box in degrees. Note that RA is input in hours-minutes-seconds, e.g. 13h, and DEC is input in degrees-minutes-seconds, e.g. 85. When a solve successfully completes, it replaces the value in the RA and DEC boxes with solution’s coordinates. In addition it fills in the Angle field with the solutions angle value in degrees.

Use SkyMap Position: There is a button just below the Use Position checkbox that fills in RA and DEC boxes with the current center of the SkyMap display.

Profile: The Profile menu selects which StellarSolver preset, among those used in the Ekos Align module, should be used for plate solving. This is further discussed below.

Solution: The Solution section will display the number of stars found and the time taken to solve. The solution values for RA, DEC, Scale and Angle are displayed in those boxes above.

Image: For any image where stars were detected, if the Mark Stars button is activated above the image display, then the detected stars are circled in red.

Using this tool the user can try and debug solving issues as follows.

He/she might have the KStars -> Settings -> Developer -> Save Failed Align Images checkbox enabled.

Then a difficult image (for whom alignment failed) could be located and loaded into the fitsviewer.

The image could be inspected to see if there were obvious visual issues.

Clicking Solve in this tool for that image would show how many stars were detected, and the user could then decide if it is a star detection issue and experiment with adjusting the profile or star-detection parameters.

The user could manually upload the image to astrometry.net to get scale and position values (or just see if it is a problematic image).

The user could experiment with Use Position and Use Scale, using accurate values for those constraints (or disabling them) to see if those were the problem, or adjust the parameters in the align profile being used.

To inspect or modify the profile, the user would open the align tab in Ekos, go to the Options menu, select the StellarSolver Options tab, make sure the right Options profile is selected, and click the pencil to view or edit that

FITS Viewer Live Stacker

The FITS Viewer Live Stacker (Live Stacker) stacks and displays subframes. It monitors a directory so can be used to stack the existing contents of the directory and / or to add new subframes as they are taken during a live session.

Multiple Live Stackers can be run to monitor different directories. These Live Stackers can be run as separate FitsViewer windows or as multiple tabs within a single FitsViewer tab. In addition, it is possible to run Live Stacker as a standalone process which is still under the control of KStars (so it is stopped when KStars itself is stopped) but has its own process space within the operating system.

Live Stacker follows the FitsViewer architectural approach of displaying the result (in this case the stacked image) and allowing existing functionality such as rotation, object highlighting, histogram manipulation, etc. to be run on the image. The stacked image can be saved by the user using the existing Save functionality.

Live Stacker operates an option webserver to serve up images to devices such as phones and tablets with web-browsers. This allows the stacked image to be viewed on individuals’ devices, for example, at star parties and outreach events.

Live Stacker operates on .fits and .xisf files. They can be either mono or color.

Dark and Flat master files may optionally be specified to improve image quality.

Each section of the Live Stacker input / output widgets are enclosed within a minimize widget that allows the block to be either expanded or minimized.

Following is a description of the UI widgets:

Stack Directory: This is the directory that Live Stacker will watch. Any files in the directory will be stacked when the Live Stacking process is started, and as new files (subs) are added to the directory these will be added to the existing stack.

Stack Directory Button: Launches a directory dialog box to choose a directory.

Multi-Channel (down arrow) button: Toggles between a single channel (either mono or color) subs and multi-channel. Multi-channel allows the user to combine mono subs into a color image. In this mode Red, Green and Blue must be specified and optionally Luminance can be added.

Proc / Fail / Total: Output statistics of the number of subs Processed successfully, Failed and the Total. The Total is the number of subs in the directory.

Webcast Button: Launch the webcast dialog that allows Live Stacker to start or stop webcasting the stacked images in the session.

Start Button: This button has 3 states:

“Start”: Pressing the button runs the stacking process on any subs in Stack Directory and watches the directory for new subs. Button text changes to “Stop”.

“Stop”: Pressing the button stops watching the directory and cancels any in-flight stacking operation. Button text changes to “Cancelling…”.

“Cancelling…”: Button cannot be pressed. When the cancel operation completes, the button text resets to “Start” and the user can start another stacking process.

Live Stacker Monitor button: Launches the Live Stacker Monitor window. See the section on Live Stacker Monitor for more details.

Calc SNR: Switch to turn on or off calculation of SNR for each sub and the stacked image. Usually useful to turn on, but if performance is key this can be toggled off.

SNR Av / Min / Max: Output statistics of the subs processed so far. Average SNR / Minimum SNR / Maximum SNR.

Memory Widget: Displays the amount of memory the current process is using as a percentage of the available memory. Try to keep memory usage in the Green (<50% of available) rather than Amber (<70%) or Red (>=70%). Double click the widget to hide text and just display the progress bar.

Image SNR: This is the SNR of the stacked image at that time.

Save Settings Button. This saves the configuration of the Live Stacker to disk.

Help button: Launches web documentation for Live Stacker.

Calibration Settings:

This section changes depending on whether single channel or multi-channel mode is selected. In single channel mode there is 1 dark and 1 flat associated with the stack dir. In multi-channel mode there is a dark and flat associated with each of the 4 stack dirs: Red, Green, Blue and Luminance.

Master Dark: Blank or pathname to a Master Dark .fits file to be used to calibrate subs.

Master Dark Button: Launches a file picker dialog box to choose a Master Dark.

Master Flat: Blank or pathname to a Master Flat .fits file to be used to calibrate subs.

Master Flat Button: Launches a file picker dialog box to choose a Master Flat.

Remove Hot Pix: Check to have Live Stacker automatically find and remove hot pixels from subframes.

Remove Cold Pix: Check to have Live Stacker automatically find and remove cold pixels from subframes.

Alignment Settings:

Master Sub: Blank or pathname to the sub to be used to align all other subs to. If blank, the first sub is used as alignment master.

Master Sub Button: Launches a file picker dialog box to choose the alignment master sub.

Method: Plate Solve. Use plate solving as the method of aligning subs.

Stacking Settings:

In Memory Subs. This specifies the maximum number of subs that will be held in-memory at any one time and specifies the number of subs that cause a transition from initial stack to running stack.

The stacking process will accumulate this number of subs (if available) before stacking them and will continue in batches of this number before stacking. If the number of subs available is less than this then the stacking process runs in order to display the stacked image to the user.

Once this number of subs is reached, the initial stacking phase completes and intermediate results are then held in order to more rapidly add new, incoming subs to the stack.

Set this number low to be more efficient with memory usage. However, if you use sigma clipping (or winsorized sigma clipping) setting this too low can compromise results.

Downscale: Options of None, 2x2, 3x3 and 4x4 are available. This options downscales the subs by the selected factor. For example, if 2x2 is selected than each group of 2x2 pixels is averaged to a single value per color, reducing both the image width and height by a factor of 2. So the number of pixels in each sub is reduced by a factor of 4 which will significantly speed up processing

Method:

Average: Frames are averaged (mean). No pixels are rejected.

Sigma Clipping: Sigma Clipping is applied to the first “In Memory Subs” to be processed. Once accumulated, a pixel stack is built for each pixel in the subs that contains the value of the pixel across all subs. The median and standard deviation of pixel values is calculated any values lying outside the thresholds of Low Sigma and High Sigma are excluded as outliers. The inliers are then used to calculate the stacked image. As new subs arrive they are checked against the saved pixel statistics to determine whether they are inliers or outliers and are processed accordingly.

Winsorized SC: Similar to Sigma Clipping except where outliers are excluded in Sigma Clipping, they are set to Low Sigma / High Sigma and included in the calculation.

ImageMM: The ImageMM stacking method based on this paper: https://iopscience.iop.org/article/10.3847/1538-3881/adfb72 Basically this can be thought of as a combination of stacking and deconvolution. The method looks to determine the most likely deconvolved stacked image that would have created the set of observed subs. It uses an iterative approach and is extremely resource intensive. This is an experimental approach at this time.

Frame Weighting:

Equal: All subs are given an equal weight (=1.0)

HFR: Subs are weighted by 1 / (Av HFR). So the better the sub, the lower the HFR and the higher the weighting.

Num Stars: Subs are weighted by Num Stars. So the better the sub, the higher than number of stars detected and the higher the weighting.

Normalization:

None: No normalization of subframes is performed.

Linear: Incoming subframes are linear normalized to the existing stack. This is the preferred method as it will stack better with subframes of various background intensity. This option will also deal better with the frame edges to avoid sharp jumps in brightness where subframes have moved slightly during the session.

Low Sigma (Sigma Clipping and Winsor SC Methods). This is the number of Standard Deviations on the low side of the median to clip pixels out.

High Sigma (Sigma Clipping and Winsor SC Methods). This is the number of Standard Deviations on the high side of the median to clip pixels out.

Winsor Cutoff (Winsor SC Method). This is the number of Standard Deviations away from the median to use as cutoff to adjust outlying values before running Sigma Clipping.

Iteration (ImageMM). This specifies the maximum number of iterations the algorithm will attempt. Increase the number for more accurate performance but at the expense of performance.

Kappa (ImageMM). Clamps iterative updates in the range 1/kappa to kappa. So kappa=1 means no update for the iteration. Increase kappa for bigger updates but if you see signs of over “deconvolving” the image then reduce kappa.

Alpha (ImageMM). Damping between iterations by blending alpha * this iteration with (1 - alpha) * last iteration.

Sigma Scale (ImageMM). Reduce calculated image sigma by this scale factor. Reduce if you see ringing artifacts.

PSF Update (ImageMM). Update PSF every nth iteration. Set to zero to disable. Updating too frequently can lead to artifacts. This is quite computationally intensive.

Post Processing Settings:

Post processing options can be turned on / off with the associated minimize widget checkbox. The system temporarily turns off post processing during the initial stacking phase to speed up processing. Thereafter, control is with the user.

These settings are applied to the stacked image to improve its appearance. There are 3 tools: Deconvolution, Denoising and Sharpening. Typically the parameters to use must be found through experimentation by the user. By changing values and hitting the Reprocess Button, the user can adjust values and rerun the Post Processing without re-running the stacking process.

Deconvolution Settings:

Wiener Deconvolution can be applied to the image. The PSF sigma to use must be specified along with an amount.

Deconv Amount: This is the amount of the Deconvolved image to blend with the original stacked image. The range is between 0 (no deconvolution) to 1 (use only the deconvolved image). Set to 0 to disable Deconvolution.

PSF Sigma. The PSF Sigma to use in the deconvolution process.

Denoising Settings:

Denoise Amount: The amount of denoising to apply. Higher values denoise more. Set to 0 to disable denoising.

Sharpening Settings:

A basic Unsharp Mask sharpening algorithm is used.

Sharpen Amount: The amount of sharpening to apply. Higher values sharpen more. Set to 0 to disable sharpening.

Sharpen Kernel. The size of the kernel used for sharpening in pixels (usually 5 or 7 works well). Choose an odd integer.

Sharpen Sigma. The sigma used in the sharpening process.

Reprocess:

Reprocess Button. Pressing this button reruns the Post Processing functionality (Deconvolution, Denoising and Sharpening) on the stacked image using the current values of the Post Processing settings. This means that on a stacked image the user can adjust settings and re-run, adjust again and re-run, etc.

Using Live Stacker for the First Time

Here are some suggestions for using Live Stacker for the first time:

Start in daylight on your imaging computer / setup with some subs you have already taken during a previous imaging session. If you have say 30 subs this will be enough to see how Live Stacker performs.

Select the directory of the subs, and press Start. The default parameters should be relatively memory efficient but may need tweaking.

See how the Memory Widget performs; you want to keep memory usage Green or at worst Amber intermittently. If you are having issues with performance and / or memory usage then here are the things to speed things up (start at the top and work down the list):

Downscale: Usually 2x2 is enough to significantly increase performance with mono subs. Color subs may need more downscaling.

In Memory Subs: Decrease this number. It will then hold less subs in memory at the same time. Note that for Sigma Clipping and Winsorised SC this will potentially compromise image quality.

Calibration Files: Adding a dark and or a flat master will improve image quality, potentially significantly, but at the cost of extra processing.

Frame Weighting: Equal is the most efficient option. Num Stars requires an extra step during Plate Solving so will always be slower. HFR requires the same extra step as Num Stars but also needs more computation so is the slowest option. HFR and Num Stars should, however, yield a better result than Equal weighting.

Rejection Method: None is much more efficient than the other options (at the cost of a potentially better result).

You can rerun the stacking process from scratch by just pressing Start, so its easy to adjust parameters and rerun.

It’s recommended to switch off Post Processing during early stages and come back to it later (see below). To do this make sure the Deconv Amount, Denoise Amount and Sharpen Amount are all set to 0.

When you have a configuration you are happy with press Save Settings and this will be the default configuration for subsequent settings.

Post Processing

When you have the settings for stacking sorted out for your equipment you may wish to try the Post Processing options. Note that the settings you choose will be applied every time Live Stacker displays a stack, e.g. when a new sub is added to the stack. For this reason when you are setting up the stack it is advisable to turn off Post Processing and then when stacking has finished, to experiment with it.

To experiment, set one of the options and press Reprocess. You can then adjust the parameter and press Reprocess again until you have the optimum settings.

Live Stacker Webcast

Pressing the Webcast button launches the Live Stacker Webcast window. This lets you control all aspects of the webcast which allows yourself and others to view stacked images on web-browsers on phones, tablets and computers. This is useful at star parties and outreach events.

The Webcast is initially stopped but is started by pressing Start. This starts the webserver and also displays a QR code in the dialog. This can be scanned to launch a web-browser on a device at the appropriate URL to receive images. Alternatively the displayed URL can be typed in.

Multiple devices can be connected.

As stacking progresses each registered device is automatically updated. The usual features of the device’s browser are available. For example, if supported, the image can be user to the device’s camera roll. The webpage can be converted to an app by the user (if this is supported on the device). This can be useful as sometimes it gives more screen space to the image and minimises decoration.

The following widgets are available: Title. Sets a title for the session - which is displayed on the device. Logo L / R: Allows a logo to be displayed to the left and right of the Title. Port: Defaults to 8080 but can be changed if required. Throttle Updates: If short exposures are causing bandwidth issues, setting this with throttle updates to clients. QR Code: Scan the QR code from a device to launch a browser on the URL URL: The URL the webcast is being broadcast on. Start Webcast: Starts the webcast Stop Webcast: Stops the webcast Reset: removes the images history of the webcast. Effectively a Stop Webcast followed by Start Webcast Subscribers: Toggle to show / hide a grid of subscribing devices to the webcast. Close: Close the Webcast dialog (can be reopened at any time).

Live Stacker Monitor

Pressing the Live Stacker Monitor button launches the Live Stacker Monitor window. The purpose of the Monitor is to display more information at the subframe level about the subs being stacked.

The Monitor displays a grid with 1 row for each sub in the directory / directories selected. The columns are configurable: right click on the column header to display a menu of columns that may be selected or deselected, or double click a column header to remove a column. In addition, the column order may be changed by clicking dragging a column header to a new location.

Single clicking a column sorts the grid on that column and toggles between an ascending sort and a descending sort.

The alignment master sub has a yellow background. If a sub fails to process it has a pink background. The “Highlighting” checkbox will also highlight cell changes as updates are processed.

Tooltips on the column headers explain what each column represents but in summary the columns represent the stacking workflow with relevant information from each step: 1. Miscellaneous columns: ID, pathname, filename, channel(s) and overall status. 2. Loading: displays timings and status of the load step and SNR of the sub. 3. Plate Solving: displays timings, status, average HFR, number of stars. 4. Stack Waiting: displays timings, status of a sub once loaded before the next stacking step. 5. Calibration: displays timings, status, Hot Pix, Cold Pix. Note that calibration is optional. 6. Alignment: displays timings, status and x, y and rotation of the sub to align with the master. 7. Stacking: displays timings, status and stacking weight.

A good way to use the Monitor is to select columns that are relevant to you and order by the ID column so most recent subs are at the top.

Single Channel vs Multi-Channel Mode

Live Stacker starts in single channel mode. This allows a single stack of either mono or color subs.

It is also possible to create color images from individual stacks of mono images. To do this, activate multi-channel mode by expanding the stack directory dropdown toggle (see the red box below) which will then display input directories for Red, Green, Blue and Luminance.

Live Stacker will then stack files in each of the directories and then watch the directories for new files. If an RGB stack is required, fill in Red, Green and Blue (and leave Luminance blank). Live Stacker will then process a stack for each channel, apply a “linear fit” between channels, and combine into a color image for display.

Optionally, a Luminance channel can be added to produce an LRGB image. In this mode, the RGB channels are combined with the Luminance channel to produce a single color image.

Narrowband filter stacks can be combined into color images: SHO, HOO, etc.

If less than 3 stacks are available, for example whilst doing an HOO image, fill in the same directory to the appropriate channels. E.g. for an HOO image set Red to the Hydrogen directory and Green and Blue to the Oxygen directory.

Running Live Stackers

Live Stacker is started by selecting “Live Stacker…” from the File menu on the KStars Skymap…

It’s possible to run more than 1 Live Stacker to monitor multiple directories. This would be useful if you are imaging multiple targets or filters and want to keep an eye on everything without having to reset the Live Stacker to a new directory periodically.

Selecting “Live Stacker…” a second time will launch another Live Stacker. Depending on how FITS Viewer is configured will determine whether multiple Live Stacker windows are started (“Single Window Capture” unchecked) or whether multiple tabs within a single Live Stacker window are started (“Single Window Capture” checked).

By default the tab name for Live Stacker is “(n) DirectoryPath” where n is the number of subs in DirectoryPath. Right click on tabname to change the name to whatever you like. This is particularly useful when runing multiple instances of Live Stacker as separate tabs.

The “Live Stacker own process” option allows Live Stacker to be started as a separate process. When “Live Stacker own process” is unchecked, Live Stacker resides in the KStars / Ekos process space. The advantage of running Live Stacker as its own process is that if it crashes it will not disturb other KStars / Ekos functionality.

Using FITS Viewer functionality with Live Stacker

Live Stacker is integrated into FITSViewer. This means that existing FITSViewer functionality can be applied to stacked images displayed in Live Stacker. For example:

Saving image stacks to disk.

Re-opening a saved stacked image.

Using blink functionality alongside stacking.

Zooming in / out.

Rotating the image

Marking stars / highlighting clipped stars

Plate solving the stacked image, although by default the stacking process will have already plate solved it.

Stretch / Histogram adjustments

Viewing image statistics / FITS Header keywords

Viewing Catalog objects (e.g. Simbad objects)

Trouble Shooting Issues

The pre-requisites for Live Stacker are that KStars is built with WCS, CFITIO and OpenCV. If any of these components is not present, the Live Stacker menu item in the SkyMap will not be visible and Live Stacker will be disabled.

Subframes need to have WCS FITS Keywords. These are added by the Indi driver when WCS is enabled. Also, on the FITS options tab in Ekos, AutoWCS should be enabled.

Live Stacker makes use of KStars internal Plate Solving so it is crucial that this is setup to work correctly. Plate Solving in KStars is flexible and functions like Align and Guide have their own Plate Solving SEP profiles. Live Stacker uses the FITSViewer Plate Solving functionality and default profile, so this is the profile to check if you have issues. Go to the Plate Solve tab in FITSViewer and see which default SEP profile you are using. Choose a different one if that works for you. Make sure you can reliably plate solve subframes with your chosen SEP profile. See the Fits Viewer Solver section of this manual for more information.

source

GitBook Guide: Create, Markdown

2026-07-26T17:19:00.000-05:00

Write Markdown directly in the editor to easily create content using common syntax

Write Markdown in GitBook.

GitBook’s editor allows you to create formatted content using Markdown.

Markdown is a popular markup syntax that’s widely known for its simplicity. GitBook supports it as a keyboard-friendly way to write rich and structured text.

You can learn more about Markdown itself by visiting Common Mark.

Text formatting

GitBook supports all the classic inline Markdown formatting:

Formatting

Markdown version

Result

Bold

**bold**

bold

Italic

_italic_

italic

Strikethrough

~strikethrough~

~~strikethrough~~

Inline code

`code`

code

Pasting Markdown

When pasting Markdown content directly into the editor, it’s important to use the Paste and Match Style option (typically Shift + Cmd + V on Mac or Shift + Ctrl + V on Windows).

If you use the standard Paste option for content copied from another editor or from the web, it may be inserted as a code block instead of formatted text.

Titles

Heading 1: # A first-level title
Heading 2: ## A second-level title
Heading 3: ### A third-level title

Code blocks

```⏎ creates a new code block.

```py⏎ creates a new code block with Python syntax highlighting.

We use Prism for syntax highlighting. You can use Test Drive Prism to check which languages Prism supports. If you notice a mismatch between GitBook and Prism, there’s a chance we’re a version or two behind. We’ll catch up soon!

Lists

GitBook automatically detects and creates ordered and unordered lists as you type.

Begin a line with - or * to start an unordered bullet list.
Begin a line with 1. to start a numbered list.
Begin a line with - [ ] to start a task list.

When writing any kind of list, hit Tab to add a indent, and Shift+Tab to outdent.

Quotes

Begin a line with > to create a block quote. If you select an entire paragraph from start to end, typing > will wrap the content in a block quote.

This is a block quote.

Dividers

Type --- then hit Enter to create a divider on your page.

This is an example of a divider.

KStars Guide the feature-rich planetarium: FITS Viewer Introduction & Main Controls..

2026-07-23T08:14:00.000-05:00

FITS, or Flexible Image Transport System, is the standard format for representing images and data in Astronomy. The KStars FITS Viewer is a tool to view those images. It is not designed for editing of FITS Images.

The FITS Viewer can be automatically invoked for images received from the camera. It can also be invoked directly from the main KStars menu. To open a FITS file, select the File → Open Image... menu item, or press Ctrl+O.

The above diagram illustrates the FITS Viewer main work area and window. There is also a hidden area that can be exposed by moving the mouse over the 6 small dots on the left side (about center of the image vertically) and pressing and holding the mouse, sliding it over to the right a bit.

Main Controls

The various controls and displays for the FITS Viewer are shown below. The tool provides basic functions for image display. While the tool adhere to the FITS standard, it does not support all possible FITS features:

Support for only one image per file.

Support for only 2D and 3D data. 1D data are discarded.

The FITS Viewer window is divided into the following regions:

Main Menu

File

Standard Open, Save, and Save As.

FITS Header: Display FITS header table data.

Debayer: Covert RAW image to RGB.

Edit

Undo: Undo last action.

Redo: Redo last action.

Copy: Copy image to clipboard.

View

Zoom Controls: Zoom in, Zoom out, standard Zoom.

Filters: Auto Stretch, Contrast, High Pass, Rotate, Flip.

Mark Stars: Detect and mark stars in the image.

Show Clipping: Display in red which stars have pixels that appear to be clipped.

Main Toolbar

Open File.

Save File: Save FITS data. Any filters applied to the image will be saved.

Save File As.

Undo last action.

Redo last action.

Zoom In: Zoom in up to a maximum of 400%. For large images this operation can be very memory intensive. Turn on Limited Resource Mode to save memory.

Zoom Out.

View in Actual Size.

Zoom to fit.

Rotate Right.

Rotate Left.

Flip Horizontal.

Flip Vertical.

Show Cross Hairs: Toggles crosshairs in the center of the image.

Show Pixel Gridlines: Toggles pixel grid.

Mark Stars: Detect and mark stars in the image.

Show Clipping: Display in red which stars have pixels that appear to be clipped.

Show Equatorial Gridlines: Toggles Equatorial Grid if FITS contains a valid WCS header.

Show Objects in Image: Identifies objects such as stars, galaxies, and nebulae within the image.

Center Telescope: Toggle Center Telescope mode. When active and if the image contains a valid WCS header, clicking anywhere in the image triggers the telescope slewing to the clicked point.

Histogram: Toggle histogram view in the side panel.

Statistics: Toggle FITS Statistic view in the side panel.

Auto Stretch: Apply Auto Stretch filter to the image.

Toggle Selection Rectangle: Toggle selection rectangle for statistics of a region of interest.

Side Panel: The side panel can be opened by dragging the separator to the right. When dragged to the left, the side panel can also be closed.

Statistics: Displays image statistics including Minimum, Maximum, Average, and Median values.

Plate Solving: A tool plate-solve the loaded image. This is useful to debug plate-solving issues.

Histogram: Displays image histogram with controls to adjust the minimum and maximum values for each channel. Both linear and logarithmic scalings are available to apply to the image. This is somewhat redundant with the below-image histogram and may be removed in the future.

FITS Header: Displays a table for FITS header keywords, values, and comments.

Recent Images: Displays recently opened images. Clicking on any image will load it.

Image Display Area.

Mouse: Hovering over the image will update the status bar values accordingly.

Mouse: Hovering over the image will move a cursor in the histogram display below the image, if that histogram is activated.

Control key: Holding down the control key and then moving the mouse will show a magnified portion of the image.

Statistics of region of interest

Provides simple statistics average mean, average standard deviation and average median of the selected region by the user in a tooltip.

The user can either set the selection region by Shift+Left Click dragging (when the selection statistics is activated) or by choosing an entry from the drop down menu of the Toggle Selection Rectangle button. In addition to this, the user can translate the region by simple Left Click drag of the mouse. The statistics of the region are shown as a tooltip once the cursor is brought over the selection region. For smaller images, the statistics are updated instantly, and for larger images, the statistics are updated once the user releases the Left Click button after modification of the region.

Stretching Controls

Near the bottom of the window are controls for stretching the image and displaying its histogram. They are described below from left to right.

Enable Stretching: On the very left of this display is a button that enables or disables stretching.

Shadow Value: The value below which pixels are displayed as black can be manually entered (scale is 0 to 1.0, even for integer pixel values).

Midtones Value: The midtones value which controls the brightness of the image can be manually entered (scale is 0 to 1.0, even for integer pixel values).

Highlights Value: The value above which pixels are displayed as white can be manually entered (scale is 0 to 1.0, even for integer pixel values).

Show Histogram: A button that displays or hides the image histogram is to the right of the highlights number box.

Auto Stretch: A button (magic wand icon) that will automatically create a pleasing stretch is found on the right. It is disabled if the stretch is already at the automatically computed value.

In addition, there are sliders that can be used to adjust the Shadow, Midtones and Highlights values. Adjusting them will change the values displayed.

The histogram, if it is enabled, may be zoomed by using the mouse’s scroll wheel, and panned by dragging with the mouse. A cursor in the histogram shows the position of the pixel in the image under the mouse.

Status Bar

From right to left, the following status indicators are available:

Loading Indicator: The LED becomes yellow when an image is getting loaded and turns green after loading is successfully done. If there are problems with loading the image, it turns red.

Resolution: Image resolution in pixels. 4656x3520 in the screenshot above.

Zoom Percentage. 13% above.

Cartesian Coordinates: Displays and updates the current mouse position as you hover over the image. X:769 Y:3508 above.

Pixel Value: Value of the pixel under the mouse. 1,792 above.

Equatorial Coordinates: If the image contains a valid WCS header, the J2000 Right Ascension (RA) and declination (DE) values are displayed. 13h 14’ 22” 42 37’ 35” above.

Image Stats: Displays the HFR, Eccentricity and number of stars if computed. HFR:1.96 Ecc:0.43 143 stars above.

Clipped Stars: If Show Clipping is activated in the main toolbar, it displays the number of possibly clipped pixels. Clip:403 above.

In addition to image display, the viewer can process World-Coordinate-System (WCS) header if present within the FITS file and provides useful information regarding the objects found within the image, equatorial grid overlay, popup menu, and the ability to slew the mount (if connected) to any point within the image.

Several filters can be applied to enhance the image include auto stretch and high contrast. Depending on the image size, these operations can take a few seconds to complete. The bottom status bar displays the current pixel value and current X & Y coordinates of the mouse pointer within the image. Furthermore, it includes the current zoom level and the image resolution.

When loading a bayered image, the viewer can automatically debayer the image if Auto Debayer is checked in the FITS Settings. The debayering operation fetches the bayer pattern (e.g. RGGB) from the FITS header. If none exists, you can alter the debayering algorithm and pattern from the File menu or by using the Ctrl+D shortcut.

Since operations such as auto debayering and auto WCS are computationally expensive and stress the processor on low-powered embedded devices, you can toggle their behavior in KStars Settings FITS page.

Hovering over any option shall display a detailed tooltip that explains its function.

source

GitBook Guide: Create, Inline content

2026-07-19T14:57:00.000-05:00

Use the inline palette to add images, links, math & TeX, and more

Add inline elements to your content.

The inline palette lets you quickly add extra content to your text block without moving your hands away from the keyboard. Simply hit / on any text block to open the inline palette. The forward slash will be replaced by the content you choose to insert.

Annotations

With annotations, you can add extra context to your words without breaking the reader’s train of thought. You can use them to explain the meaning of a word, insert extra information, and more. Readers can hover over the annotated text to show the annotation above the text.

Create an annotation

To create an annotation, select the text you would like to annotate and click the Annotate option in the context menu. Once you’ve written your annotation, click outside of it to continue writing in the text block.

Markdown representation

You can write content as Markdown footnotes to add them as annotations in GitBook. Footnote indicators should appear immediately after the word you wish to annotate; they should not appear after punctuation marks or other symbols.

Copy

Here's a simple footnote[^1], and here's a longer one[^bignote].

[^1]: This is the first footnote.

[^bignote]: Here's one with multiple paragraphs and code.

    Indent paragraphs to include them in the footnote.

    `{ my code }`

    Add as many paragraphs as you like.

Images

Inline images will sit alongside your text on the page.

By default, images are set to their original size with a maximum width of 300px. You can change the size by clicking the image to open the formatting palette, then choosing one of the three options:

Inline size: The image is proportionally sized to the font — great for icons and badges.
Original size: The image will remain inline at its original size, with a maximum width of 300 pixels.
Convert to block: This turns an inline image into a image block, which is as wide as your content.

Image blocks offer more options, including more sizes and the ability to add a caption — but will not appear inline with your text.

Representation in Markdown

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Here is an inline image: <img src=".gitbook/assets/GitBook - Dark.jpg" alt="Dark version of GitBook logo" data-size="line">

Emojis

You can add emojis by hitting / to open the inline palette. Alternatively, type : and a list of emojis will pop up directly in line — you can start typing the name of an emoji to narrow down the selection.

Representation in Markdown

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:house:
:car:
:dog:

Links

You can insert three different types of links:

Relative links

Relative links are links created by linking to pages that already exist in your space. The advantage of using relative links is that if the page’s URL, name, or location changes, its reference will be kept up to date — so you’ll end up with fewer broken links.

Here’s how to insert a relative link:

Click somewhere in your paragraph where you want to insert the link, or select some text.
Hit / to open the inline palette and choose Link, click the Link button in the context menu, or hit ⌘ + K.
Start typing the title of the page you want to link to.
Select the page from the drop-down search results.
Hit Enter.

Absolute links

Absolute links are external links that you can copy and paste into your content. They’re great when you want to link to something outside your documentation.

To insert an absolute link:

Click somewhere in your paragraph where you want to insert the link, or select some text.
Hit / to open the inline palette and choose Link, click the Link button in the context menu, or hit ⌘ + K.
Paste the URL you want to link to.
Hit Enter.

Why don't external links open in a new tab?

When you add a link to an external site in your docs, it will open in the same tab.

GitBook follows this W3C-recommended behavior to support accessibility and ensure a consistent, inclusive experience for your readers.

Email address mailto links

Email address mailto links are useful when you want your visitors to click on a link that will open up their default email client and fill in the To field with the email address of your link, so they can write an email to send.

Here’s how to insert an email address mailto link:

Click somewhere in your paragraph where you want to insert the link, or select some text.
Hit / to open the inline palette and choose Link, click the Link button in the context menu, or hit ⌘ + K.
Paste or type mailto:something@address.com, replacing something@address.com with the email address you would like to use.
Hit Enter.

Representation in Markdown

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[This is a relative link to another page in this space](../content-structure/page.md)
[This is an absolute link](https://www.gitbook.com/blog)
[This is a link](mailto:support@gitbook.com) to our support email address

Math & TeX

Using this option, you can create an inline math formula in your content, like this: <?XML:NAMESPACE PREFIX = "[default] http://www.w3.org/1998/Math/MathML" NS = "http://www.w3.org/1998/Math/MathML" />f(x)=x∗e2piiξxf(x)=x∗e2piiξx. We use the KaTeX library to render formulas.

You can also insert a block-level math formula by opening the command palette in an empty block and choosing the second Math & TeX option.

Representation in Markdown

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# Math and TeX block

$$f(x) = x * e^{2 pi i \xi x}$$

Buttons

Buttons are a great way to describe calls to action. You can use them to send users to other pages in GitBook, or to external URLs.

Buttons have both primary and secondary styles. Here are a couple of examples:

Representation in Markdown

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<a href="https://app.gitbook.com" class="button primary">GitBook</a>

Icons

Icons allow you to add extra visual indications to your site. You can add them inline to paragraphs, inside a card, or anywhere else you need to add some flair. They will use the visual style defined in your customization settings.

Visit Font Awesome to explore the different icons available.

Representation in Markdown

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<i class="fa-github">:github:</i>

Expressions

Expressions allow you to dynamically display content defined in a variable. Expressions can be inserted from the / menu. Once inserted, double clicking on the expression will bring up the expression editor, allowing you to reference and conditionally format your variable.

KStars Guide the feature-rich planetarium: Ekos Extensions, AI Assistant (MCP).

2026-07-16T08:11:00.000-05:00

Extensions are small programs that can be added to interact with Kstars/Ekos/INDI in order to provide extra functions and features.

Note

Extensions are separate from Kstars/Ekos/INDI. They are not provided as part of this software. Only a means to call them is provided for convenience. Make sure that you understand the requirements and risks of using an extension.

Requirements

Each extension must consist of at least 2 files, with an optional third icon file.

The program file. This is any executable file that will run on the users system. The user under which KStars is running must have execute permission on this file.

The configuration file. This is a plain text file that defines the required and optional inputs for the extension. It must be named the same as the extension executable with the addition of a .conf file name extension.

It is mandatory that the configuration file contains a line starting with minimum_kstars_version=n.n.n where n.n.n is the lowest version of KStars that supports the extension e.g. 3.7.3

Optionally (and non-preferred) the configuration file may contain a line starting with runDetached=true. If present this line makes the extension run independently from KStars. Once it has been started the extension can not pass status information back to Ekos. This should only be used by extensions that are required to continue to run after KStars has closed. The extension must also provide its own user interface.

Additionally the configuration file can contain any other parameters that the extension author decides and free text.

The icon file, if present, must be named the same as the extension executable with the addition of the appropriate file name extension for the image format, .jpg, .bmp, .gif, .png and .svg are supported. If provided this icon will be used in the extension selection ComboBox. If an icon is not provided a default icon will be used instead.

All files of the extension (executable, configuration, and optional icon) must be copied into the KStars writable data location /extensions e.g. ~/.local/share/kstars/extensions

Extensions that are present, have a valid configuration file, and have a minimum KStars version no higher than the current installation will be detected when Ekos is started. If there are no valid extensions detected the extension UI element will not be displayed. The extension UI elements are a ComboBox showing the name and icon of each detected extension, and a start/stop button. If the extension fails to close within 10 seconds of the stop button being clicked, it becomes re-enabled as an abort button that will force close the extension. Only one extension can be used at a time.

Development

The following describes additional points for developers of extensions.

Some extension sources including an example skeleton extension are available in the KStars Extension Github

Each extension must check for the existence and validity of its own configuration file. The minimum_kstars_version configuration file entry must be checked against an internal reference to confirm that the configuration file matches the extension requirements. See the skeleton example.

The calling KStars version is passed to the extension as arg(1) in the launching QProcess call.

All interaction with KStars/Ekos/INDI should be via the DBus interface. See the skeleton example. Useful tools for interrogating, monitoring and understanding DBus include D-Feet and Bustle

It may appear on initial investigation that using the Qt DBus Adaptors system would be much easier than direct use of the Qt DBus Interfaces/Messages and KStars does provide the required xml definitions. However currently there is heavy use of custom types, the definitions of which are combined with other information in the KStars sources. This results in a large set of files from KStars that require inclusion within an extension in order to make use of the Qt DBus Adaptors. Hopefully this will be addressed in the future.

AI Assistant (MCP)

Introduction

Ekos embeds a Model Context Protocol (MCP) server. MCP is an open standard that lets AI assistants and agents discover and call tools exposed by an application. With the MCP server enabled, an AI assistant can observe your rig — connection status, mount position, the last captured image — and, if you allow it, operate the mount and focuser, resolve catalog targets, and more.

Any MCP-capable client can consume the server out of the box: it speaks standard JSON-RPC 2.0 over HTTP, with the usual initialize, tools/list and tools/call methods. No KStars-specific client code is required.

Enabling the Server

The server is configured in the Ekos settings dialog, in the MCP tab.

Check Enable MCP server to start it. The server starts automatically with Ekos whenever this option is enabled.

Port selects the TCP port to listen on. The default is 8765; any port between 1024 and 65535 may be used.

The status LED next to the port shows whether the server is currently listening.

Note

The server only listens on the local machine (127.0.0.1). It is not reachable from the network. To use it from another machine, you need to set up your own tunnel (for example an SSH port forward) and understand the security implications of doing so.

Authentication and Tokens

Every request must carry a bearer token. Two tokens are managed in the MCP tab, each with show, copy and Regenerate buttons:

The Token field holds the full-access token. Clients presenting it can call every enabled tool.

The Read-only token field holds a separate token restricted to read-only tools. Give this one to assistants that should observe the rig but never move hardware.

Tokens are stored in your system keychain (under the service name kstars), never in plain-text configuration files. Regenerating a token immediately invalidates the previous one.

To connect a client, point it at http://127.0.0.1:8765/mcp and pass the token as a standard HTTP bearer credential. Requests are JSON-RPC 2.0 messages sent with POST. For example, calling the ekos_status tool with curl:

curl -s http://127.0.0.1:8765/mcp \
  -H "Authorization: Bearer <your token>" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc": "2.0", "id": 1, "method": "tools/call",
       "params": {"name": "ekos_status", "arguments": {}}}'

The response is a JSON-RPC envelope whose result carries the tool output — here the INDI connection state, the active profile, and the connected devices.

A Server-Sent Events stream is available at /mcp/stream. Each connection is rate-limited to 60 requests.

Safety Controls

Warning

A full-access token allows an AI agent to move your mount and focuser. On a live rig, treat that token like a password: prefer the read-only token whenever observation is enough, and review which tools are enabled before handing control to an agent.

Three mechanisms limit what a connected client can do:

Read-only mode (refuse rig control tools). When checked, the server refuses every mutating tool for all clients, regardless of which token they present.

The read-only token. Clients authenticating with it can only call tools marked read-only, even when read-only mode is off.

The Available tools tree. Every tool the server exposes is listed here, grouped by family, with a checkbox per tool and per family. Unchecked tools are hidden from clients entirely: they disappear from tools/list and calls to them are rejected.

In the tree, a lock icon marks read-only tools and a gear icon marks tools that change the state of the rig. Tooltips also indicate tools whose effect is hard to undo (such as mount_sync), following the annotation hints of the MCP specification.

Tool Reference

The tables below list the tools currently shipped with KStars. The Access column shows read for tools that only observe the rig and control for tools that change its state.

Ekos Status

Tool

Purpose

Access

ekos_status

Current INDI/Ekos connection status, active profile, and connected device names.

read

Catalog

Tool

Purpose

Access

catalog_search

Search the KStars catalogs by name. Returns matching objects with canonical names, types, J2000 coordinates and magnitudes. Supports substring or exact match, a type filter, and a magnitude limit. Use it to resolve a name like “M42” to the canonical “M 42” before slewing.

read

Mount

Tool

Purpose

Access

mount_coords

Current RA/Dec, Alt/Az, hour angle, pier side and tracking status.

read

mount_get_slew_rates

List the slew rates supported by the driver and the currently selected one.

read

mount_goto

Slew to equatorial coordinates (RA in hours, Dec in degrees).

control

mount_goto_target

Slew to a named object, resolved by KStars (canonical name, e.g. “M 42”).

control

mount_sync

Sync the mount pointing model to the given coordinates. Hard to undo — a wrong sync corrupts the pointing model.

control

mount_park / mount_unpark

Park the mount at its park position, or unpark it for operation.

control

mount_abort

Immediately stop all mount motion.

control

mount_set_tracking

Enable or disable sidereal tracking.

control

mount_set_track_mode

Select the tracking rate: sidereal, lunar, solar or custom.

control

mount_set_slew_rate

Select a slew rate by index into the driver’s list.

control

mount_set_meridian_flip

Enable or disable the automatic meridian flip and set its hour-angle offset.

control

Focuser

Tool

Purpose

Access

focuser_status

Focuser name, current and maximum position, and capability flags. An optional name parameter selects a device on multi-focuser rigs; all focuser tools accept it.

read

focuser_move_absolute

Move to an absolute step position, validated against the driver’s maximum. Must not be called while Ekos autofocus is running.

control

focuser_move_relative

Move by a signed number of steps (positive outward, negative inward; direction is driver-dependent). Must not be called while Ekos autofocus is running.

control

focuser_abort_move

Stop any in-flight focuser motion.

control

Image Access

These tools see frames from every producer: the Capture queue, Focus, Align, polar alignment, and ad-hoc captures. On a multi-camera rig, an optional camera parameter selects a device; by default the most recent frame across all cameras is returned.

Tool

Purpose

Access

image_last_info

Metadata of the most recently captured frame: file path, camera, exposure, filter, target, timestamp, sensor temperature, HFR, star count and dimensions.

read

image_last_thumbnail

A base64-encoded JPEG preview of the most recent frame, sized for vision-capable models (default 512 pixels on the long edge, at most 1024).

read

source

GitBook Guide: Create, Formatting your content

2026-07-12T17:42:00.000-05:00

Format your content in various ways using the context menu or keyboard shortcuts

To format your text, simply select the words you want and choose one of the formats from the context menu — or format your text using a keyboard shortcut or through Markdown syntax.

We’ve written these shortcuts using Mac keys. Use Control in place of ⌘ (Command) on Windows or Linux operating systems. Check out our keyboard shortcuts section to see all the shortcuts for all operating systems.

Bold

Keyboard shortcut: ⌘ + B

Markdown

Copy

**Bold**

Italic

Keyboard shortcut : ⌘ + I

Markdown

Copy

_Italic_

Strikethrough

Keyboard shortcut: ⇧ + ⌘ + S

Markdown

Copy

~~Strikethrough~~

Code

Keyboard shortcut: ⌘ + E

Markdown

Copy

`Code`

Link

Keyboard shortcut: ⌘ + K

When you add a link to text on your page, you’ll be prompted to provide the link. You can add any URL, but if you’re linking to another page or section in your space, we recommend using a relative link.

This is a link to an external page.

This is a link to another page in this space.

This is a link to a section on this page.

This is a link that starts an email to a specific address.

Color and background color

Click the color icon in the context menu, and choose a color for the text or its background.

This text is orange.

This text background is orange.