2010 EU65

2010 EU₆₅ is a centaur, approximately 64 kilometers (40 miles) in diameter, orbiting the Sun in the outer Solar System. The object is also a promising Uranus horseshoe librator candidate.^[8] It was first observed on 13 March 2010, by American astronomers David Rabinowitz and Suzanne Tourtellotte, observing from Cerro Tololo and La Silla Observatory in Chile.^[1][2][3] As of 2021^[update], it has neither been numbered nor named.^[1]

2010 EU₆₅

Discovery[1][2][3]
Discovered by	D. Rabinowitz S. Tourtellotte
Discovery site	La Silla Obs.
Discovery date	13 March 2010 (First observed only)
Designations
MPC designation	2010 EU65
Minor planet category	centaur[4][5][6]
Orbital characteristics[4]
Epoch 1 July 2021 (JD 2459396.5)
Uncertainty parameter 3[4] · 2[1]
Observation arc	10.12 yr (3,698 d)
Aphelion	22.939 AU
Perihelion	17.009 AU
Semi-major axis	19.974 AU
Eccentricity	0.1484
Orbital period (sidereal)	89.27 yr (32,606 d)
Mean anomaly	0.1061°
Mean motion	0° 0m 39.6s / day
Inclination	14.572°
Longitude of ascending node	4.6718°
Time of perihelion	21 June 2021[a]
Argument of perihelion	240.15°
TJupiter	2.94
Physical characteristics
Mean diameter	64 km (est. at 0.09)[5]
Apparent magnitude	21.71[7]
Absolute magnitude (H)	9.1[1][4]

Orbit and classification

2010 EU₆₅ is classified as a centaur, a group of non-resonant small Solar System bodies whose orbit around the Sun lie typically between the orbits of Jupiter and Neptune (5 to 30 AU). Centaurs are minor planets with characteristics of comets, and often classified as such. The dynamical group is formed due to Neptune's eroding effect on the Kuiper belt by means of gravitational scattering, sending objects inward to become centaurs, or outward to become scattered-disc objects, or removing them from the Solar System entirely. Centaurs themselves have unstable orbits with short lifetimes, transitioning from the inactive population of Kuiper belt objects to the active group of Jupiter-family comets within approximately one million years.

It orbits the Sun at a distance of 17.0–22.9 AU once every 89 years and 3 months (32,606 days; semi-major axis of 19.97 AU). Its orbit has an eccentricity of 0.15 and an inclination of 15° with respect to the ecliptic. It has a Tisserand's parameter with respect to Jupiter (T_J) of 2.94, near the threshold of 3, typically used to distinguish asteroids from Jupiter-family comets.^[4] On 21 June 2021, the object came to perihelion at 17.0 AU and has since been moving away from the Sun.^[a] As of 2021^[update] the object is at 17.009 AU, with a apparent magnitude of 21.71.^[7] The body's observation arc begins with a precovery observation taken by the Mount Lemmon Survey in April 2009.^[1]

Uranus horseshoe candidate

Based on its current heliocentric orbit, 2010 EU₆₅ follows a horseshoe orbit around Uranus' L₃ point. Giving the fact that its orbit is, at present, poorly determined, the object is a promising Uranus horseshoe orbiter candidate.^[8]

Physical properties

2010 EU₆₅ has an absolute magnitude of 9.1. Based on a generic magnitude-to-diameter conversion, it measures approximately 64 kilometers (40 miles) in diameter assuming an albedo of 0.09.^[5]

See also

• List of centaurs (small Solar System bodies) § 2010 EU65

Notes

1. JPL Horizons Observer Location: @sun (Perihelion occurs when deldot changes from negative to positive.)