NGC 1499 (California Nebula)

The emission nebula NGC 1499 (California Nebula), in the constellation Perseus. The nebula's shape resembles the outline of the U.S. state of California. The nebula's extent is about 100 light-years, and its distance from Earth is 1500 light-years. An emission nebula is a cloud of ionized gas that emits light in the visible spectrum. The California Nebula has a red color, characteristic of hydrogen atoms recombining with electrons that were previously knocked out of the atoms during ionization by high-energy photons. The most likely source of the ionizing radiation is the hot blue star ξ Persei, visible in the photo below and to the right of the nebula itself... Scale 50%.