More Backyard Astronomy 12/7/2020. If you liked astronomy photographs as a child, then you probably liked the Horse Head Nebula (Barnard 33) in the Constellation Orion, the Hunter. The Horsehead is that little dark nebula made up of gas and dust which looks like a chess piece on a platter of very red ionized hydrogen in the photograph. The bright star just a bit to the left is Alnitak, which is the end star on the left side of Orion's belt. It was put there to blind astronomer's eyes when looking for the Horse Head in the eyepiece of a telescope. It is very difficult to see in a telescope. The little horse head is about 3 to 4 light years tall and maybe 2 to 3 light years wide. The nebula is about 1,375 light years away from the end of my telescope. If you aren't familiar with the term "light year" that is how far light travels at 186,000 miles a second for a year.

Just below Alnitak is the Flame Nebula NGC 2024. This is an emission nebula made up of ionized hydrogen gas which glows from energy of Alnitak exciting the electrons in the gas and causing them to emit the light which we see. The Horse Head, the gas cloud, and the Flame Nebula is a playground of heavenly delights. All that you can see in this photograph is called the Orion Molecular Cloud Complex.

I have always wanted to photograph the Horse Head Nebula since I started into astrophotography. To do this photograph I captured approximately 7.5 hours of camera exposures using a Hydrogen Alpha and an Oxygen III filter to bring out the colors of the various gases. I didn't use film. Instead thecamera basically counts electrons in each pixel on a monochrome chip in my camera. Astronomers call this "data." I took 134 separate exposures, some with one filter or the other. The exposures ranged from 2 to 5 minutes. The exposures download from the camera to my computer so that I can use other software to process the data. I am still learning and my work is a work in process.

I hope you enjoyed my photograph. Have a Happy Chanukah or a Merry Christmas. Stay safe.