Hunting the Horsehead (and Other Christmas Eve Sites)

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!)

The 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.Next 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 8x42 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.

Winter 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.

Reprinted with permission from the Half-Astrophysicist Blog.