California Nebula (NGC 1499)
The California Nebula (NGC 1499) is an emission nebula located in the constellation Perseus. It is so named because it appears to resemble the outline of the US State of California on 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 Ha line in the nebula by the nearby prodigiously energetic O7 star, xi Persei (also known as Menkib, seen near the center of the image).
[description from wikipedia]