The Omega Nebula, also known as the Swan Nebula taken in Ha from my Creedmoor site October 4th, 2016. Catalogued as Messier 17 or M17 the Omega Nebula is an H II region in the constellation Sagittarius. It was discovered by Philippe Loys de Chéseaux in 1745. Charles Messier catalogued it in 1764. It is located in the rich starfields of the Sagittarius area of the Milky Way.