M-17 (NGC-6618) is a diffuse hydrogen emission nebula located in the constellation of Sagittarius. It is commonly called the "Omega" or "Swan" nebula. It more closely resembles an upside-down swan. This nebula lies approximately 5,700 light years from Earth and is 22 light years in diameter. M-17 is a vast interstellar cloud of hydrogen gas and dust, and is an area of intense star formation. It was discovered by de Cheseaux in 1745. Charles Messier added it to his catalog as number 17 in 1764.
This image, acquired on July 14, 2012, is a 30 minute integration of 90 second exposures through the Celestron C-11 at f/2 using the HyperStar III imaging system and the Starlight Express SXVR-H694C color CCD camera operating at -10 degrees below ambient temperature and binned 1 X 1. Guided, captured and combined using Maxim DL5 Pro. Post processed using PhotoShop CS2, Gradient XTerminator, StarShrink, Carboni's Astro Tools and NoiseWare.