| Discovery date 27 December 2009 Alternative names 2004 PR107, 2009 YS20 Observation arc 4631 days (12.68 yr) Absolute magnitude 18 Asteroid group Asteroid belt | MPC designation (392741) 2012 SQ31 Minor planet category Main belt Discovered 27 December 2009 Orbits Sun | |
| Discovered by Cerro Tololo Inter-American Observatory (807) | ||
(392741) 2012 SQ31, also known as 2004 PR107, 2009 YS20 and 2012 SQ31 is an asteroid in the asteroid belt with an absolute magnitude (H) of 17.8. It was discovered on August 11, 2004 by Cerro Tololo Inter-American Observatory, and then lost due to a lack of follow-up observations.
With an observation arc of only 1 day (consisting of only two images), 2004 PR107 was thought to be a trans-Neptunian object with a semi-major axis (a) of 46 AU. Mike Brown's website listed it as a likely a dwarf planet with an estimated diameter of 555 km. It was rediscovered in 2009 as 2009 YS20, but was not identified at the time as being related to 2004 PR107. The lost asteroid was rediscovered as 2012 SQ31 and determined to be a small, ~1-kilometer asteroid in the asteroid belt. Precovery images from December 5, 2002 have been located.