September 24, 2008
Minor planet category
154.47 AU (23.108 Tm)
745 days (2.04 yr)
24 September 2008
Argument of perihelion
M. E. Schwamb M. E. Brown D. L. Rabinowitz
Michael E. Brown, David L. Rabinowitz
(84922) 2003 VS2, (119951) 2002 KX14, (229762) 2007 UK126, 65489 Ceto, 38083 Rhadamanthus
2008 ST291, also written as 2008 ST291, is a trans-Neptunian object with an absolute magnitude of 4.2, making it possibly a dwarf planet.
2008 ST291 is estimated to be about 612 kilometres (380 mi) in diameter, assuming a typical albedo of 0.09 for trans-Neptunian objects. However, because its albedo is unknown and it has an absolute magnitude of 4.2, it could be anywhere between 370 and 820 km in diameter.
2008 ST291, currently 60.1 AU from the Sun, came to perihelion around 1954. It takes over one thousand years to orbit the Sun. Of the known and suspected dwarf planets, only Sedna, 2012 VP113 and 2005 QU182 are known to have longer orbits.
2008 ST291 has only been observed 26 times over three oppositions and has an orbit quality of 5 (0 being best; 9 being worst).