123P/West–Hartley

< 123P

123P/West–Hartley
Discovery image of Comet West–Hartley taken from ESO on 11 May 1989.
Discovery
Discovered byRichard M. West
Malcolm Hartley
Discovery siteEuropean Southern Observatory
Discovery date11 May 1989
Designations
P/1989 E3, P/1995 S2
1988 XVI, 1989k
Orbital characteristics
Epoch7 October 2026 (JD 2461320.5)
Observation arc30.39 years
Number of
observations
4,399
Aphelion5.616 AU
Perihelion2.159 AU
Semi-major axis3.887 AU
Eccentricity0.44469
Orbital period7.665 years
Inclination15.281°
45.848°
Argument of
periapsis
103.88°
Mean anomaly1.945°
Last perihelion5 February 2019
Next perihelion21 September 2026
TJupiter2.832
Earth MOID1.197 AU
Jupiter MOID0.704 AU
Physical characteristics
Mean radius
2.18±0.23 km
3.7 hours
Comet total
magnitude
(M1)
8.2
Comet nuclear
magnitude (M2)
13.8

Comet West–Hartley is a periodic comet with a 7.67-year orbit around the Sun.