(148975) 2001 XA255

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
(148975) 2001 XA255
Discovered byDavid C. Jewitt, Scott S. Sheppard and Jan Kleyna
Discovery date9 December 2001
MPC designation(148975) 2001 XA255
Orbital characteristics[1]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 2
Observation arc3812 days (10.44 yr)
Aphelion48.731 AU (7.2901 Tm)
Perihelion9.3364 AU (1.39671 Tm)
29.034 AU (4.3434 Tm)
156.44 yr (57141.1 d)
0° 0m 22.681s / day
Jupiter MOID4.12722 AU (617.423 Gm)
Physical characteristics
Mean diameter
12.5 km[2]
37.700 km[1]

(148975) 2001 XA255, provisional designation 2001 XA255, is a dark minor planet in the outer Solar System, classified as centaur, approximately 20 kilometers in diameter.[1] The object is currently trapped in a 1:1 mean-motion resonance with Neptune following a path of the horseshoe type.[3]


2001 XA255 was discovered on December 9, 2001 by David C. Jewitt, Scott S. Sheppard, and Jan Kleyna observing from the Mauna Kea Observatory.[4]


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.[1]

Physical properties[edit]

The object has an estimated diameter of 12.5 km and it was classified as an inactive centaur by David C. Jewitt.[2] Observations by the NEOWISE mission gave a larger diameter of 37.7 kilometers and an albedo of 0.041. It has an absolute magnitude is 11.1.[1]

Resonance with Neptune[edit]

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.[5] 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.[3]


  1. ^ a b c d e f g "148975 (2001 XA255)". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. Retrieved 7 April 2016.
  2. ^ a b Jewitt, David C. (2009). "The Active Centaurs". The Astronomical Journal. 137 (5): 4296–4312. arXiv:0902.4687. Bibcode:2009AJ....137.4296J. doi:10.1088/0004-6256/137/5/4296.
  3. ^ a b de la Fuente Marcos, C.; de la Fuente Marcos, R. (2012). "Four temporary Neptune co-orbitals: (148975) 2001 XA255, (310071) 2010 KR59, (316179) 2010 EN65, and 2012 GX17". Astronomy and Astrophysics. 547: L2. arXiv:1210.3466. Bibcode:2012A&A...547L...2D. doi:10.1051/0004-6361/201220377.
  4. ^ Jewitt, David C.; Sheppard, S. S.; Kleyna, J.; Marsden, B. G. "2001 XA255". Minor Planet Electronic Circular.
  5. ^ ADS link Gallardo, T. (2006) Atlas of the mean-motion resonances in the Solar System

External links[edit]