Polish amateur comet hunter Arkadiusz Kubczak recently discovered his third comet in SOHO LASCO coronagraph images, but this one was special: the 1000th SOHO comet discovery in the Kreutz group of sungrazing comets.
While there is no formal definition of a ‘sungrazing comet,’ the term typically refers to the Kreutz-group comets, which have a perihelion distance of less than 0.01 of an Astronomical Unit (the mean distance between the Earth and the Sun), or some 1460000 km.
The 1185th comet discovered in data from the SOHO LASCO or SWAN instruments (the other 185 are not members of the Kreutz group), the faint object is officially designated C/2006 P7 (SOHO) by the Minor Planet Center of the International Astronomical Union.
Before the launch of SOHO in 1995 December, only some thirty members of the Kreutz group were known. All 1000 Kreutz comets are believed to be fragments of a single comet observed in c. 371 BCE by Aristotle and Ephorus, and the fragments themselves continue to fragment, making more sungrazing comets.
