A group of apparently related long-period comets with very small perihelion distances (less than 0.01 au). They are named after the German astronomer Heinrich Carl Friedrich Kreutz (1854–1907), who studied them in 1888. Sungrazer orbital elements fall into two subgroups, travelling in retrograde orbits with periods of about 500–1000 years. It thus appears that the sungrazers are derived from the break-up of a single large progenitor (perhaps similar to Chiron), and the further disintegration at subsequent returns of two or more of its fragments. Notable sungrazers include the Great September Comet of 1882 and Comet Ikeya–Seki in 1965. Numerous sungrazers have been discovered by coronagraphs aboard spacecraft, over three thousand of them by the Solar and Heliospheric Observatory (SOHO). See also sunskirter.

http://sohowww.nascom.nasa.gov/pickoftheweek/old/22oct2010/