California Nebula

Object Type: Emission Nebula
Scope: 80 mm APO Refractor
Exposure 360 minutes

The California Nebula (NGC 1499/Sh2-220) is an emission nebula located in the constellation Perseus. Its name comes from its resemblance to the outline of the US State of California in long exposure photographs. It is almost 2.5° long on the sky and, because of its very low surface brightness, it is extremely difficult to observe visually. It lies at a distance of about 1,000 light years from Earth. Its fluorescence is due to excitation of the Hβ line in the nebula by the nearby prodigiously energetic O7 star, Xi Persei (also known as Menkib). The California Nebula was discovered by E. E. Barnard in 1884. By coincidence, the California Nebula transits in the zenith in central California as the latitude matches the declination of the object.