(418993)_2009_MS9
(418993) 2009 MS9
Centaur roughly 30–60 km in diameter
(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.[lower-alpha 1]
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.[2]
It came to perihelion in February 2013 at a distance of 11 AU from the Sun (outside the orbit of Saturn).[4] As of 2016[update], it is 12 AU from the Sun.[6]
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.[3]