(148975) 2001 XA255

(148975) 2001 XA₂₅₅, also written as 2001 XA255, is a minor body classified as centaur by the Minor Planet Center.^[1] The object is currently trapped in a 1:1 mean-motion resonance with Neptune following a path of the horseshoe type.^[2]

Discovery

(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.^[3]

Orbit

(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.^[4]

Physical properties

The object has an estimated diameter of 12.5 km and it was classified as an inactive centaur by David C. Jewitt.^[5] Its absolute magnitude is 11.2.^[4]

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.^[6] 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.^[2]

References

External links

• 2001 XA255, Jewitt, D. C., Sheppard, S. S., Kleyna, J., & Marsden, B. G. 2002, Minor Planet Electronic Circular, 2002-A85.
• The Active Centaurs, Jewitt, D. C. 2009, Astronomical Journal, Volume 137, Number 5, pp. 4296–4312.
• (148975) 2001 XA₂₅₅ data at MPC
• Atlas of the mean motion resonances in the Solar System Gallardo, T. 2006, Icarus, Volume 184, Issue 1, pp. 29–38.
• Four temporary Neptune co-orbitals: (148975) 2001 XA255, (310071) 2010 KR59, (316179) 2010 EN65, and 2012 GX17 de la Fuente Marcos, C., & de la Fuente Marcos, R. 2012, Astronomy and Astrophysics, Volume 547, id.L2, 7 pp.
• IAU list of centaurs and scattered-disk objects
• IAU list of trans-neptunian objects
• Another list of TNOs