Samiksha Jaiswal (Editor)

(148975) 2001 XA255

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Discovery date  9 December 2001
Minor planet category  Centaur
Aphelion  48.731 AU (7.2901 Tm)
Inclination  12.628°
Discovery site  Mauna Kea Observatories
MPC designation  (148975) 2001 XA255
Observation arc  3812 days (10.44 yr)
Discovered  9 December 2001
Argument of perihelion  90.452°
Asteroid group  Centaur
Discovered by  David C. Jewitt, Scott S. Sheppard and Jan Kleyna
Discoverers  Scott S. Sheppard, Jan Kleyna, David C. Jewitt
Similar  Scott S Sheppard discoveries, Other celestial objects

(148975) 2001 XA255, also written as 2001 XA255, is a minor body classified as centaur by the Minor Planet Center. The object is currently trapped in a 1:1 mean-motion resonance with Neptune following a path of the horseshoe type.



(148975) 2001 XA255 was discovered on December 9, 2001 by David C. Jewitt, Scott S. Sheppard, and Jan Kleyna observing from the Mauna Kea Observatory.


(148975) 2001 XA255 follows a very eccentric orbit (0.68) with perihelion just inside the orbit of Saturn, aphelion in the trans-Neptunian belt and a semi-major axis of 28.9 AU. The orbital inclination of this object is moderate at 12.6º.

Physical properties

The object has an estimated diameter of 12.5 km and it was classified as an inactive centaur by David C. Jewitt. Its absolute magnitude is 11.2.

Resonance with Neptune

(148975) 2001 XA255 was identified as trapped in a 1:1 mean-motion resonance with Neptune and 1:2 with Uranus by T. Gallardo in 2006. The object is dynamically unstable and it entered the region of the giant planets relatively recently, perhaps 50,000 years ago, from the scattered disk. It follows a short-lived horseshoe orbit around Neptune.


(148975) 2001 XA255 Wikipedia