ToddSpace: John's Astrophotography Page

Celestial Elephant Trunk

2007-09-12T12:41:57-04:00

Here's a fascinating object in the constellation Cepheus, the King. This is just to the north of the constellation cygnus, the swan. It can be found directly overhead on warm summer evenings, but unfortunately, it's barely visible to the naked eye. I photographed this gem using narrowband filters, Oxygen-III, Sulfur-II and HydrogenAlpha from Baader. Each of these filters isolated a single emission (light) line from the nebula. I took these three images and combined them in photoshop, assigning each of them a color, OIII - blue, S2 - Red and HA - green, this is commonly referred to as the hubble palette. The color of this image should look somewhat familiar as that's what the hubble space telescope produces for public consumption. This is a grand total of 480 minutes of exposure time with my Tak E-160, Canon 350xt and Losmandy G11 mount. I also threw some difraction spikes onto the brighter stars for good measure. Can you make out the "elephant trunk" in the image? This "dark nebula" is simply a thick cloud of insterstellar "dust" pushing through an active area of Sulfur, Oxygen and Hydrogen Alpha. VDB142, as it is more commonly referred to, is not very visible at all under all but the most ideal of conditions.

Photography with ordinary canon lenses

2007-06-19T12:43:30-04:00

I've gone over this before, but it never ceases to amaze me the quality of images you can get with an ordinary DSLR and good high quality lenses. The only thing you need beyond these things are a means by which to do long exposure photography (a shutter release cable) and a tracking mechanism. The stars move through the nighttime sky at a clip of about 23 hours 56 minutes for a complete revolution, this means that the star right above your head will be exactly in the same place 23:56:00 later. I use an ordinary telescope mount for tracking, either a losmandy g-11 or losmandy gm-8, both of them do a fine job. Here's a couple of shots I took while up in Maine last month (May). The first is of the antares region of the sky, Antares is the bright orange summer star riding low in the horizon in the constellation scorpio. If you look to the south this time of year, you'll see this beautiful twinkling star. In the i

If you look to the south this time of year on a clear dark evening, you'll see that star twinkling about 30 degrees off the horizon. This area of the sky is laden with interstellar dust clouds which are illuminated by the bright stars in that area. In this photo, taken with an ordinary canon 200mm f/4 L lens, you can see bright clouds of dust illuminated by Antares as well as bright blue areas illuminated by the triple star system rho ophiuchi. Such a glorious sight in the summer time, but only viewable through long exposure photography.

On the right you'll see one of my favorite sites of all, the summer milky way in all its glory. This was a simple 15 minute exposure taken with a friends f2.8 16-35mm canon lens set to 24mm. When sitting out doors after dark on a clear summer evening, with your eyes protected from any source of bright lights, your eyes will become more and more sensitive and eventually you'll believe you see some clouds stretching across the sky. those aren't clouds but rather the star clouds of the summer milky way. If this site doesn't make you a closet astronomy fan, then nothing will!

Rosette Nebula - Narrowband Imaging

2007-04-12T09:28:32-04:00

One of the modern day challenges of astrophotography is how to deal with light pollution. Lets say you go out and spend $10k-$20k on all the right equipment to get yourself to the same level as all the best amateurs in the hobby and night after night all your looking at is dull skies awash in light pollution. For you imagers within 5-10 miles of a major metro area, you know how painful this can be. I actually live within 5 miles of Manchester to the east and Nashua to the south, so I generally need to photograph away from those directions, directly overhead, west and north are good areas of the sky for me, however, every once in a while I want to shoot something that lies in that area of the sky that’s awash in light pollution. Narrowband imaging to the rescue! Fortunately, sky pollution is very predictable and so is the light from DSOs (deep sky objects) that I want to gather. The subject photo in this blog entry is the rosette nebula which was located in the south west in some heavy light pollution when I photographed it.

The problem of course with light pollution is that your camera can’t tell the difference between incoming light, be it from the DSO or from your local 7-11 lighting up the sky. With this particular image, I shot the rosette using two different filters, the first being a Baader-planetarium Hydrogen-alpha (HA) filter. The HA filter isolates the glowing red of the nebula and blocks all other incoming light. The second part of the photo was taken with a Baader-Planetarium Oxygen-3 (OIII) filter, which records the teal color of triply ionized oxygen. These two exposures were both about two hours each and allowed me to create grayscale images of these two dominant spectral lines of the rosette nebula. Using photoshop, I used the OIII image for blue, the HA image for red and combined the two to create a synthetic green channel, these three “channels” (to use photoshop-speak) make up the RGB (red green blue) image attached. Comparing this image to a rosette nebula shot at a very dark, light pollution free sight, there is very little difference other than the dominance in the image of the OIII (bluish-purple). This image is absolutely a false color image, but done so in a way to try and as realistically reproduce what is seen from a dark sky.

This second image is of the same rosette nebula from a dark sky sight, notice the dominance of the red (hydrogen-alpha) which overwhelms the picture. It’s a matter of aesthetics as to which one would like more, but to me, the mere fact that I can continue to shoot from my backyard despite the light pollution makes the argument between false color and true color moot.

The Crowned Jewel of the Winter Skies

2007-02-07T12:24:06-05:00

One of the most common misconceptions in astronomy and astrophotography is that you need a large telescope to get anything done. Nothing could be further from the truth. To prove this point I went out and took a photo of the great orion nebula in the winter constellation Orion with a common 300mm canon L lens, please click on the thumbnail below to view that. The only special equipment I used to get this photograph was a telescope mount that's capable of moving through the sky at the 'sideareal' rate (one complete revolution every 23 hours 56 minutes). With this mount (a Losmandy G11) properly aligned with the north celestial pole, all I did was bungee cord the camera and lens to the mount and took several 5 minute exposures to generate this photo, no telescope involved at all. Why is this? Fact is, most of the DSOs (deep sky objects) we find fascinating in the heavens are quite large, some as large if not larger than the full moon. We have come to believe that it takes large telescopes to view these objects, this is not the case at all, what it takes is a patient eye and dark skies. To photograph them it just takes something that will move through the sky at the same rate as the stars, typically a precision GEM (German Equitorial Mount).

So this past December (06), I generated both of these images, one with a 300mm canon lens and the other with my Tak E-160 telescope. What is it that we're looking at? This is one of the prettiest areas of the sky with just oodles of active star birth going on. On the left is what's known as "the running man nebula", a blue star cluster that illuminates the dark interstellar dust lanes giving this the shape of a "running man" (do you see him?). On the right is the great orion nebula, one of the VERY FEW DSOs that is visible to the naked eye. To find the orion nebula, locate Orion's belt, this is fairly easy, look for the three bright stars in a row seperated by about two fingers widths at arms length. Right below Orion's belt is three dim stars making up his sword, the center of these three "stars" is actually what's pictured here, the Orion nebula. If you have a pair of binoculars, spend some time getting your eyes dark adapted and enjoy the view, it's quite a treat.

One last note here, so one of these photos was taken with a 300mm lens, the other with a $2k telescope, have I proven my point about the non-necessity of getting into this hobby with a big telescope?

Would like to know more about taking astrophotos? Visit my how to take an astrophoto page on my website.

Presenting John Lanoue's Astrophotography Page!

2006-12-31T08:58:00-05:00

Ever wonder how I was able to take those incredible astrophotos over at my original weatherman.com website? Well there are tricks of the trade. I'm happy to report that fellow astrophotographer John Lanoue is not only going to publish some of his best photos (which now put mine to shame) right here on this astrophoto blog, but he will share HOW he does it with YOU! Since I stopped taking photos 3 years ago the technology has made it easier for you to do it at home, using digital cameras. Welcome, John, show us your stuff! - Todd Gross

A celestial pony and his flame

2006-12-20T12:27:36-05:00

Here's a neat trick when shooting the heavens. If you live in a light polluted area or just want to shoot in black and white, try a Hydrogen-Alpha filter. The filter I use, from Baader, isolates the Hydrogen Alpha wavelength (the deep red of nebulas) and lets no other light through the filter. The result is a very contrasty image with almost no ambient light pollution. This allows you to photograph nebulas as if you were shooting from deep in the woods of northern Maine with not a hint of light pollution for a hundred miles or more. I did this photograph from my backyard in Bedford, NH

This photograph is of the famous horsehead nebula and it's companions, the bright winter star Alnitak and the flame nebula. These nebulas are both bisected with thick clouds of interstellar dust giving the appearance of black lanes within the nebulas. This particular photo is a composite of 15 10 minute exposures with my Canon 350d and Takahashi E-160 telescope. This stellar nursery is 1600 light years away from Earth, the nearest star birthing region to us, literally in our celestial backyard. I create black and white shots like this by cutting the red channel out of the photo and pasting it into the blue and green channels in photoshop, this gives grayscale.

This, as well as all my other photographs, are posted at http://www.bedfordnights.com

Next up... The Great Orion Nebula!

Our Sister Galaxy, Andromeda

2006-11-15T12:46:37-05:00

On cool crystal clear autumn evenings, that's the best time to view our sister galaxy, M31, the Andromeda Galaxy. This galaxy is generally recognized as the furthest celestial object from the Earth which can be viewed with the naked eye. This galaxy is easily viewed under clear dark skies, in fact, you've probably viewed it before and wondered what it was as it shows up as a smudge just to the northeast of the Great Square of Pegasus.

This celestial object is located 2.9 million light years from Earth and as mentioned, is easily visible to the naked eye, it's a wonderful sight in binoculars and even a more amazing sight under a moderately powerful telescope with good optics. This past September I viewed M31 from up in Maine and managed for the first time to see the dust lanes that bisect the galaxies core.

This galaxy is gravitationally bound to our galaxy, the Milky Way. Scientists estimate that the Milky Way galaxy and the Andromeda Galaxy are on a collision course and will some day have a cataclysmic encounter! Don't fret too much, this is predicted to happen in about 11billion years, so we have plenty of time to plan :-)

This photograph was taken this past September from my backyward in Bedford, NH using my Tak E-160 telescope and my modified canon 350d. It is a composite of 15 5 minute exposures. If I take this photo again this year, I will reduce the exposure time to try to bring out some detail in the core of the galaxy which is completely washed out in this photo.

So next time you're under a clear dark sky in the Autumn, look directly overhead for that "smudge" just to the north east of the Great Square of Pegasus, now you know what it is.

The Veil Nebula supernova remnant

2006-09-21T12:44:22-04:00

The veil nebula is not like other nebulas that I've posted here. The veil nebula is whats known as a supernova remnant, in other words, all that is left of a star in our milky way galaxy that exploded about 5,000-10,000 years ago in the constellation cygnus. Although there are no historical records of this happening, it undoubtedly threw the ancients into a panic. This supernova remnant is huge, the distance between the eastern and western clouds of expanding matter is 6x that of the full moon! Below is the Eastern limb of the veil nebula.

I have only twice directly viewed the veil nebula, both on extraordinarily still clear dark evenings, once naked eye and once via binoculars, once again, as with other nebulas, your eye is not sensitive enough to pick out the colors so even if you are fortunate enough to view this, the full glory of is expanding wall of gas is only fully viewed and appreciated in long exposure photography. Here's an interesting feature of this nebula: My daughter first pointed this out to me during the post processing stage. My daughter Laura is a fanatical swimmer, spends the entire summer in the water, but always with her goggles... can you see the pair of goggles intertwined with the tendrils of gas? Click on the thumbnail on the left for a larger image. She immediately pointed out to me "Daddy, look, the goggle nebula!". This photo clearly shows the gasseous tendrils of hydrogen and triply ionized oxygen, the two dominant spectral wavelengths of this particular supernova. This photon on the left is simply a closeup taken from the full resolution photo of the eastern limb.

Here's another section of the veil nebula, NGC6960, more commonly referred to as "the witches broom". This is the western most section of the nebula, you can also see in this photo some additional hydrogen alpha (red) which makes up whats known as pickerings triangle, or Pickerings wisp. Once again, these are just two parts of the entire veil, I was not able to fit the whole thing into one field of view because of its size. Both of these photos were taken in early September, they were composites of 20 5 minute exposures taken with my modified canon 350d and takahashi e-160. I also used a hutech light pollution filter called an IDAS LPS, this is the best filter out there for combating light pollution as it narrows in on specific sources of light pollution, like mercury vapor and sodium halide, typical street light emissions. Any requests? I have the glories of autumn coming up soon, andromeda in particular (our sister galaxy).

The Lagoon and Trifid Nebulas

2006-08-31T13:04:45-04:00

Here in New England, us astrophotographers are faced with a considerable challenge when pursuing some of the most stunning deep sky objects our galaxy (the milky way) has to offer. While the constellation cygnus rides directly up above on summer evenings and is filled with billowing clouds of nebulous gas, some of the most stunning astrophotography targets unfortunately lie much closer to Sagittarius which never rises much more than about 25 degrees over the southern horizon. This means that in order to capture these colorful gems, one must pack up and head for a dark field in the middle of nowhere. On the night of Friday August 25th I did just that, heading out to Chesterville Maine with about 200lbs of astro-gear for a remote imaging session. Problem with these sessions is to do advanced astrophotography, you have to have about 100 things in just the right place and everything must go right, which fortunately, it did that night. The following night my shutter cable failed so I went the same way as the sox in September, downhill.

Fortunately, on the night of the 25th I was able to shoot the Lagoon and trifid nebulas, a colorful celestial pair that ride just above the spout of sagittarius' teapot. On a clear dark night, you can easily see the lagoon nebula as a ill defined patch of greyish light. The trifid nebula, being much smaller, is much more difficult to see. This particular photograph is a composite of 6 5 minute exposures with my Tak E-160 (f3.3) and my canon 350d. Nice thing about havnig a laptop in the field that evening with me is I could sit in my car while the laptop automated everything for me, this was particularly useful as a friendly skunk paid me a visit around 1:00am.

The Trifid nebula was so named because a dark dust lane trisects it into three distinct nebulas, although later visual observations tagged it a "four lobbed nebula". Here is a closeup of the trifid nebula. Surrounding the trifid nebula you'll see a bright blue reflection nebula... it's referred to as a reflection nebula because it doesn't emit its own light, rather, it's just the reflection of nearby bright blue starlight off of interstellar dust clouds.

A closeup of the Lagoon nebula reveals one of the most fascinating elements of the dynamics of our milkyway, and it also eludes to the vastness of it. In the closeup below, you can see dark lanes that look to be about the size of a tadpole swimming through this vast nebulous ocean:

Click on the thumbnail to view. These tiny dark lanes are collapsed clouds of protostellar dust and are not tiny, they measure about 10,000 AUs in width... how big is that? An AU is an astronomical unit which is 93,000,000 miles, the distance from the earth to the sun. In other words, incomprehensibly large... and just barely discernable from earth based telescopes. Kind of gives you an appreciation for the vastness of space!

I've had a few requests for some of these photos to be used as desktop wallpaper, if you're interested feel free to email me.

Next up... the Veil nebula, an expanding supernova remnant.

The North American and Pelican Nebulas in Color

2006-08-23T13:06:07-04:00

In the last week I've had two wonderful clear dark skies to get out and photograph this gem that crosses the zenith around 10:00pm this time of year (August). As previously photographed, these aer the pelican and north american nebulas shot through my Takahashi E-160 telescope and my modified canon 350d. The first shot is a hydrogen alpha only photograph:

Click on this thumbnail to see the full resolution photograph. The deep thick knots of nebulosity here show up as almost white. Using a deep red hydrogen alpha filter I am able to reject all sources of light pollution and isolate just the nebula itself, this results in a very very rich nebula field in a fairly short exposure. This is a grand total of 15 minutes exposure time. Both of these nebulas are visible to the naked eye in VERY dark skies just to the southeast of the bright summer star Deneb.

Next up is the same photograph only shot in color. Whenever I post a color photo like this the immediate response is "cool! will I see that in my telescope?", the answer sadly is no way in hades! Reason is is that this is a very dim nebula with all of its surface brightness spread out over a very large area. Because of this, your eye will tend to see grey, this is the natural tendency of our eyes when faced with discerning the shape or color of a very dim object. However, long exposure photography solves this dilemna for us as the camera serves to collect light over a long period of time giving us all the glorious detail seen in this photos. This is a 42 minute total exposure time. Six individual 7 minute photos were combined in photoshop to generate this image. I've been asked before how come I don't just take a 42 minute exposure and why go through the process of compositing so many sub exposures? Answer is simple, these images all build up noise on the sensor (all electronic light sensors build up noise, unwanted grain shows up on the image), by layering them you increase the signal to noise ratio, in other words, the more photos, the more nebula, and the noise is random, so it ends up cancelling out all the noise of the other images, so you end up with a nice smooth background. There are some wonderful tutorials on this on the web. Next up is the trifid and lagoon nebulas, a colorful section of the sky with both red hydrogen alpha emission and blue reflection nebulas intersected with dark dust lanes.