Object Analysis

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 degrees long on the sky and, because of its very low surface brightness, it is extremely difficult to observe visually.

The nebula lies at a distance of about 1,000 light-years from Earth. Its fluorescence is due to excitation of the hydrogen gas in the nebula by the extremely energetic star Xi Persei (also known as Menkib), located just outside the nebula to the south.

By coincidence, the California Nebula transits in the zenith in central California as the latitude of the nebula matches that of the state. It is a classic example of an H II region, glowing red due to the recombination of electrons with ionized hydrogen protons.