Atmospheric Aquiline

Today I have a rather stunning image (if I say so myself) that I apparently took back in October 2009. I say that because I don't remember reducing the data, and yet I discovered it today sitting in a folder about 90% of the way to being finished. So I finished it, and it turned out to be quite a beauty.

(Edit 3/31/18: In retrospect, while I started learning to use the imager fairly quickly I wonder if this wasn't data given to me by the guy who taught me how to use it as October 2009 was when I first came up to the VIS. That would fit with me not remembering having reduced it. So if that is the case, sorry for taking your credit all these years Nathan.)

Messier 16, the famous Eagle Nebula in Sagittarius.

This is the famous Eagle Nebula, entry #16 in Charles Messier's famous list of not-comets. It is a place of stellar birth, where clouds of gas and dust are contracting into new stars. The faint red glow you see throughout the region comes from hydrogen excited by the many young, hot, massive stars in the area which are emitting copious quantities of ultraviolet light. The red light is called hydrogen-alpha by astronomers and has a wavelength of 656.28 nanometers. It comes about when the electron of a previously excited hydrogen atom jumps down from the third shell of orbitals surrounding the nucleus to the second, releasing a photon of red light in the process.

The Eagle Nebula achieved stardom (ha!) mainly after 1995 when an iconic picture of it was taken with the Hubble space telescope that focused on the dark dust lanes seen near the center. These became known as the Pillars of Creation, and are believed to be locations where stars are actively being born.

If you're wondering why it's called the Eagle Nebula, as with most such names it works better if you're looking at it through a moderately-sized telescope. You can kind of see it in deeper images that reveal more of the outlying details, as well.