| Discovery date 25 June 2009 Minor planet category Centaur Discovered 25 June 2009 Absolute magnitude 9.9 Apparent magnitude 21 | MPC designation (418993) 2009 MS9 Observation arc 2352 days (6.44 yr) Aphelion 102.325032 trillion m Asteroid group Centaur | |
| Perihelion 11.002 AU (1.6459 Tm) (q) Semi-major axis 353 AU (barycentric 2050) 347.6 AU (a) Discovered by Canada–France–Hawaii Telescope (568) Similar 2012 DR30, 2007 TG422, (148209) 2000 CR105, 2012 VP113, Sungrazing comet | ||
(418993) 2009 MS9, provisionally known as 2009 MS9, is a centaur roughly 30–60 km in diameter. It has a highly inclined orbit and a barycentric semi-major axis (average distance from the Sun) of ~353 AU.
2009 MS9 has a well determined orbit and has been assigned a minor planet number. Objects such 2009 MS9 may be the origin of Halley-type comets.
It came to perihelion in February 2013 at a distance of 11 AU from the Sun (outside the orbit of Saturn). As of 2016, it is 12 AU from the Sun.
It will not be 50 AU from the Sun until 2047. After leaving the planetary region of the Solar System, 2009 MS9 will have a barycentric aphelion of 696 AU with an orbital period of 6640 years.
In a 10 million year integration of the orbit, the nominal (best-fit) orbit and both 3-sigma clones remain outside 8.3AU (qmin) from the Sun.