 Necklace Nebula

The Necklace Nebula (PN G054.2-03.4) is a 19-trillion-kilometre-wide ( light-year-wide) planetary nebula located about 15,000 light-years away in the northern constellation Sagitta.It was discovered in 2005 from the Isaac Newton Telescope Photometric H-alpha Survey (IPHAS), a ground-based H-alpha planetary nebula study of the North Galactic Plane.