C/1989 Y2 (McKenzie–Russell)

Comet McKenzie–Russell, formally designated as C/1989 Y2, is a hyperbolic comet that was discovered by Australian astronomers, Patricia McKenzie and Kenneth S. Russell on December 1989.

For other comets discovered by Kenneth S. Russell, see Comet Russell.

C/1989 Y2 (McKenzie–Russell)

Discovery[1]
Discovered by	Patricia McKenzie Kenneth S. Russell
Discovery site	Anglo-Australian Observatory
Discovery date	21 December 1989
Designations
Alternative designations	1989f1[2] 1989 XVIII
Orbital characteristics[3]
Epoch	30 December 1989 (JD 2447890.5)
Observation arc	50 days
Earliest precovery date	19 December 1989
Number of observations	45
Perihelion	1.976 AU
Eccentricity	0.99999
Inclination	160.366°
Longitude of ascending node	293.896°
Argument of periapsis	191.736°
Last perihelion	7 November 1989
TJupiter	–1.641
Earth MOID	0.9962 AU
Jupiter MOID	1.4407 AU
Comet total magnitude (M1)	10.0

Discovery and observations

Robert H. McNaught reported the discovery of a new comet that Patricia McKenzie found on photographic plates that Kenneth S. Russell took on 21 December 1989.^[1] Prediscovery images from Japan were taken in 19 December 1989 but went unnoticed until the next year.^[4] Orbital calculations of the comet revealed it was already on its outbound flight as it had reached perihelion a month before discovery, and as a result it continued to fade away in the following days.^[5] It was last observed on 24 January 1990.^[6]