Aphelion 47.427 AU
|Minor planet category Trans-Neptunian object|
|Discovered by List
Hsing Wen Lin
Matthew J. Holman
Matthew J. Payne
Wesley C. Fraser
Richard J. Wainscoat
John L. Tonry
Eugene A. Magnier
Discovery date 31 May 2011 rediscovered 2015 by Pan-STARRS
Named after A Chinese adjective meaning "rebellious"
(471325) 2011 KT19 (nicknamed Niku) is a trans-Neptunian object (TNO) that has an unusual 110 degree tilted solar orbital plane and retrograde orbit around the Sun.
It was discovered some time in 2015, and announced in August 2016 by a team of astronomers using the Pan-STARRS telescope, and was soon linked with a supposed prograde Centaur that had been lost, designated 2011 KT19. Notably, it is part of a group of objects which orbit the Sun in a highly inclined orbit; the reasons for this unusual orbit are unknown as of August 2016.
The orbital characteristics of 2011 KT19 have been compared to those of 2008 KV42 (Drac). The orbits of 2011 KT19, 2008 KV42, and four other objects appear to occupy a common plane, with three in prograde and three in retrograde orbits. The probability of this alignment occurring by chance is 0.016%. These orbits should leave a common plane in a few million years because the precessions of prograde and retrograde orbits are in opposite directions. Simulations including the hypothetical Planet Nine did not maintain a common orbital plane and the plane does not coincide with the plane of the predicted high-inclination large semi-major axis objects of that model. Other simulations with a few Earth-mass dwarf planet on a high-inclination orbit also failed to reproduce the alignment.