M17

M17 is also known as the Swan Nebula or NGC 6618, it is also known as the Horseshoe Nebula.But those names are just alternative names. Its original name is Omega Nebula and it is 3/4° across at its widest, and is variously described as being shaped like a Greek letter omega, a horseshoe, a swan, or the figure 2. It lies about 5000 l.y. away in the constellation Sagittarius.