4544 Xanthus

4544 Xanthus /ˈzænθəs/, provisional designation 1989 FB, is an asteroid, classified as near-Earth object of the Apollo group, approximately 1.3 kilometers in diameter. It was discovered on 31 March 1989, by astronomers Henry Holt and Norman Thomas at the Palomar Observatory in California.^[2]

Xanthus

Orbit diagram of Xanthus as of March 2013
Discovery
Discovered by	Henry Holt and Norman G. Thomas
Discovery site	Palomar Observatory
Discovery date	31 March 1989
Designations
MPC designation	(4544) Xanthus
Pronunciation	/ˈzænθəs/[1]
Alternative designations	1989 FB
Minor planet category	Near-Earth object Apollo
Orbital characteristics[2]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 0
Observation arc	7629 days (20.89 yr)
Aphelion	1.3023 AU (194.82 Gm)
Perihelion	0.78120 AU (116.866 Gm)
Semi-major axis	1.0418 AU (155.85 Gm)
Eccentricity	0.25012
Orbital period (sidereal)	1.06 yr (388.38 d)
Mean anomaly	269.26925°
Mean motion	0° 55m 36.923s / day
Inclination	14.146°
Longitude of ascending node	24.00998°
Argument of perihelion	333.75°
Earth MOID	0.173705 AU (25.9859 Gm)
Physical characteristics
Dimensions	1.3 km
Mean radius	0.65 km
Synodic rotation period	37.65 h (1.569 d)
Absolute magnitude (H)	17.1