5145 Pholus

5145 Pholus
	Pholus (circled) photographed by the Sloan Digital Sky Survey at Apache Point Observatory on 28 April 2003
Discovery
Discovered by	Spacewatch; (D. Rabinowitz uncredited);
Discovery site	Kitt Peak National Obs.
Discovery date	9 January 1992
Designations
MPC designation	(5145) Pholus
Pronunciation	/ˈfoʊləs/
Named after	Φόλος Pholos; (Greek mythology)
Alternative designations	1992 AD
Minor planet category	centaur; distant;
Symbol	or (astrological)
Orbital characteristics
	Epoch 1 July 2021 (JD 2459396.5)
	Uncertainty parameter 1 · 0
Observation arc	40.74 yr (14,881 d)
Earliest precovery date	22 July 1977
Aphelion	31.943 AU
Perihelion	8.7531 AU
Semi-major axis	20.348 AU
Eccentricity	0.5698
Orbital period (sidereal)	91.79 yr (33,526 d)
Mean anomaly	117.26°
Mean motion	0° 0m 38.52s / day
Inclination	24.617°
Longitude of ascending node	119.44°
Argument of perihelion	354.77°
Jupiter MOID	3.495 AU
Saturn MOID	0.34961
TJupiter	3.21
Physical characteristics
Mean diameter	99±15 km
Synodic rotation period	9.980 h
Geometric albedo	0.155±0.076
Spectral type	Tholen = Z; RR (very red); RR-U; B−V = 1.19; V−R = 0.78;
Apparent magnitude	21.62; 16.3 (Perihelic opposition)
Absolute magnitude (H)	7.1; 7.198±0.056 (R); 7.63;

5145 Pholus /ˈfoʊləs/ is an eccentric centaur in the outer Solar System, around 100 kilometers (62 miles) in diameter, that crosses the orbit of both Saturn and Neptune. It was discovered on 9 January 1992 by American astronomer David Rabinowitz (uncredited) of UA's Spacewatch survey at the Kitt Peak National Observatory in Arizona, United States. The very reddish object has an elongated shape and a rotation period of 9.98 hours. It was named after the centaur Pholus from Greek mythology.