Discovery date September 24, 2008 Minor planet category TNO (SDO) Aphelion 154.47 AU (23.108 Tm) Inclination 20.8234° Mean anomaly 22.781° | MPC designation 2008 ST291 Observation arc 745 days (2.04 yr) Discovered 24 September 2008 Argument of perihelion 324.37° Apparent magnitude 22.2 | |
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Discovered by M. E. Schwamb
M. E. Brown
D. L. Rabinowitz Discoverers Michael E. Brown, David L. Rabinowitz Similar (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.
Contents
Size estimate
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.
Distance
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).