The California Nebula (NGC 1499) is an emission nebula in the constellation Perseus the Hero. Because of its large size, NGC 1499 is notoriously difficult to observe but rather easy to photograph. It lies about 1,000 light-years away.

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 can be observed with a Hβ filter (isolates the Hβ line at 486 nm) in a rich-field telescope under dark skies. It lies at a distance of about 1,000 light years from Earth. Its fluorescence is due to excitation of the Hβline in the nebula by the nearby prodigiously energetic O7 star, Xi Persei (also known as Menkib, seen at center below it in the inset at right).

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.