This image of a central portion of the Andromeda Galaxy is only a combined 36 minutes of exposure (9x4'). I was testing to see what kind of exposures I will eventually need to take a real image of this amazing galaxy, the nearest major galaxy to our Milky Way. After I calibrated and combined the images and began to stretch the histogram of the combined frame, I wondered if I might see some globular clusters around the galaxy. I know that amateurs with large scopes often hunt them down. Perhaps I could see a few, too?
A web search led me to Robert Gendler's amazing image of M31 in which he has labelled a bunch of globs. I compared my image with his and found quite a few matches. Going to the source of his labels, Paul W. Hodge's Atlas of the Andromeda Galaxy, I realized that I could see not just a few but very many. I have not labelled all of those that I found, actually. Some are too faint to see unless the image is blown up, and some are located near the center of the galaxy where Hodge's plates, or at least those found on the website, are too blurred or noisy to read. But I have labelled sixty-four, many more than I thought I would find.
Not bad for 36 minutes through an 80mm scope.
Telescope: Stellarvue SV80ED NHNG f/7 w/WO ff/fr 0.8 II (so effectively at f/5.6)
Camera and Exposure: SXVF-H9C, 9x4'
Filter: IDAS-LPS2
Guiding: Borg 50mm, Meade DSI Pro, PHD
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Photoshop CS3
Location: The Woodlands, TX
4 comments:
That's really something else. Both the shot and that you have time to sit down and label all of those globs! Regardless, superb photo and information. I had no idea.
Thanks, Phil! The image is a little noisy (or at least over-processed to hide the noise)---M31 needs another 30 hours! But the glob positions were fun to plot. It was quite an interesting project. Besides, we've now been under heavily clouded skies for nearly two weeks. If one can't image, or even look, perhaps one can find things in prior images. Exploring the universe, one small set of pixels at a time!
I knew that they were out there, somewhere, but I had no idea how to locate them. Thanks for the info! I did a quick comparison of one of my M31 images to yours and found quite a few globs. I might reimage it to see if I can bring out some more detail.
Post 'em up, Rory! I was pretty surprised. It's the only way a fellow like me with lots of kids and no time to hit a dark sky sight could see them. And then I get to show them to my family and friends!
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