Location of Photo:
Pommier Observatory, Portland, OR, USA
Date/Time of photo:
2018-07-10 through 2018-07-18.
Telescope/Mount: Celestron Compustar C14 with Starizona LF reducer/corrector (f/7.5). Camera: SBIG STL 11000M with Baader Planetarium Ha,R,G,B filters. Adaptive Optics: SBIG AO-L at 8 Hz.
Messier 17 is an emission nebula and star forming region lying about 5,500 light-years from Earth in the constellation Sagittarius. It may have more nicknames than any other nebula. It is known as The Swan Nebula because the bright central portion looks like a swan swimming on water with neck and head arching around the dark nebula near the center, with wings and tail behind, and a water line below. The neck and body of the swan look like a check mark, particularly through telescopes, so it is also known as The Check Mark Nebula. The bright portion wrapped around the dark nebula resembles a capital Greek letter omega, giving it the name The Omega Nebula. Similarly, a capital omega looks like a horseshoe, which lends the name The Horseshoe Nebula.