|Discovery date 18 June 2002|
Alternative names none
Orbital period 269 years
Discovery site Palomar Observatory
|MPC designation 2002 MS4|
Observation arc 20569 days (56.31 yr)
Discovered 18 June 2002
Apparent magnitude (V) 20.6
|Discovered by Chad Trujillo,
Michael E. Brown|
Minor planet category Cubewano (MPC) ScatExt (DES)
Discoverers Michael E. Brown, Chad Trujillo
Similar Michael E Brown discoveries, Other celestial objects
(307261) 2002 MS4 is a large classical Kuiper belt object, the second-largest known object in the Solar System without a name, after 2007 OR10. It was discovered in 2002 by Chad Trujillo and Michael Brown.
Brown's website lists it as nearly certain to be a dwarf planet. The Spitzer Space Telescope estimated it to have a diameter of 7005726000000000000♠726±123 km. The Herschel team estimates it to be 7005934000000000000♠934±47 km, which would make it one of the 10 largest TNOs currently known and large enough to be considered a dwarf planet under the 2006 draft proposal of the IAU. It is currently 47.2 AU from the Sun and will come to perihelion in 2123.
It has been observed 55 times, with precovery images back to 1954.