The Half-Astrophysicist Blog

Hunting the Horsehead

When I was in grade school and first getting into astronomy, the Horsehead Nebula was one of the most intriguing objects in the sky. It was on the top of the list of things I wanted to see. When I got my first little 60mm refracting telescope, I spend hours scanning Orion looking for it, never finding it…and of course never listening to people who told me (correctly) that it was WAY beyond the reach of a 60mm telescope!

Earlier this week, I had the pleasure of going out on a shoot with an excellent astrophotographer, Sean Parker (if you don’t know his stuff, go look now!) He wanted to try out the iOptron Skytracker I had and he had borrowed a Canon 5D Mk III and a 70-200 f/2.8 lens so we had some great equipment to play with.

He took several shots of Orion using different exposures and got the Horsehead! I was thrilled to see this, but since this is a lifelong obsession of mine, I wasn’t quite satisfied. I wanted to get a pic of it with my camera and my lens (even though neither my camera or lens are as good as what he was using). So Christmas Eve, I went out with my Canon 60D and EF-s 55-250mm zoom lens. Since my lens can’t operate at f/2.8, I had to use longer exposure and higher ISO, but am pleased to report that yes, I got everything (although I didn’t take and blend multiple exposures…I have a way to go before I get as good as Sean!)

IMG_8953The Orion Nebula is at the bottom right with the Running Man just to its upper left. In the far upper left of the image is the Flame Nebula. Now look closely in the pinkish haze to the lower right of the Flame and you will see a VERY small dark horsehead shape. I got the nebula! Yes, I nerd out over that.

Although this is the shot I really wanted, I of course took some others as well. I will start off with the Andromeda Galaxy.IMG_8943Next I will go for the Pleiades. Notice the gas around it. We used to think (and some astronomers still mistakenly will say) that this is the cloud of gas and dust in which these young stars were born. However, the IRAS (Infrared Astronomy Satellite) mission showed that the stars were plowing through this gas at a high rate of speed. IRAS showed the shockwaves as the stars interact with the gas. Given the very different velocities of the stars and gas, this is almost certainly not where they were born.


The constellation of Auriga has a wealth of star clusters as it is in the heart of the winter Milky Way. A wide shot can capture three of them at once. M37 is the bottom of the three, M36 is the middle and M38 is at the top. The Messier objects aren’t really in any particular order around the sky! These are all open clusters. The stars were born at the same time from the same cloud of gas and dust, but they are not gravitationally bound to each other so the stars will scatter around the galaxy as time goes on. They are not quite close enough together to get all three in the field of view of my 8×42 binoculars at one time…I can get either the two and the third will be just outside the field of view!


I will make one more stop here. This pari of galaxies is M81 and M82 about 10 million light years away in Ursa Major. M81 (on the right) is a spiral galaxy much like our own Milky Way. M82 on the left is an irregular galaxy (sometimes nicknamed the Cigar Galaxy) that recently passed nearby M81. The gravitational interaction between the galaxies led to a burst of star formation in M82. M82 is called (appropriately) a starburst galaxy.

IMG_8977Winter in Tucson is a great time to observe. The nights have not been too cold and the skies have been clear. I hope to get out and do some very wide field stuff in the next few days and hope that it is clear this weekend as we have our great ISS passes coming up.


December 26, 2013 - Posted by | Astrophotography, Galaxies, iOptron Skytracker, Uncategorized


  1. That was very interesting and I love the pictures, they are beautiful.

    Comment by Paige | January 5, 2014 | Reply

  2. Great shots! You have done quite well with the equipment you have. I’d encourage you to take things to the next level, though. Stacking is very easy, even if you don’t have a tracking mount, stacking with a tool like DeepSkyStacker is pretty easy. It will align your images for you, and if you take enough frames, it can GREATLY reduce the noise. Once your noise is reduced, you can “stretch” the darker details in a tool like Photoshop to greatly enhance those dimmer objects like IC434 (the actual source of the pinkish-red glow behind horse head.) You don’t necessarily need tracking to do this either. You can do it with your 5D III and 70-200/2.8 on a standard tripod. Just use a remote shutter release that allows you to program in multiple exposures. Turn on live view (which puts the mirror up and keeps it up), bulb mode, expose at the lowest ISO you can get away with for the longest possible time before start trailing. Even if you can’t quite see the IC434 nebulosity, if you stack 20-50 frames, that won’t be a problem…you can just lift that dim detail with curves in photoshop after the fact. It just takes a little experimentation to get right, and next thing you know your making some amazing images that are much closer to what Sean Parker is getting.

    No need to take things slow. 😉 You might also look into some other software to support focusing. If you could use f/2.8 at a low ISO and stack, you could get some truly amazing images. Look into BackyardEOS. It’s a program that offers some very fine-grained focusing features that will allow you to very precisely focus at f/2.8, and it allows you to create programs to take sequences of frames. You can set up such a program to take a short sequence of frames, then pause, then take another sequence, then pause. The usefulness here is that on a non-tracking mount with very wide field stuff (i.e. anything under 200mm), the sky will move across your frame. You want to take exposures while the subjects you are interested in are still reasonably close to the center of your frame. Once they move out, you need to re-frame, then take another sequence. BYEOS installed on a laptop or a windows 8 tablet can REALLY help you here, and it isn’t all that expensive (I think the fully featured version is $50). They have a trial version…I highly recommend you check it out. I just started using it myself, and it’s amazing. I think you could go really far with it.

    Comment by Jon Rista | February 27, 2014 | Reply

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