C/1989 Y1 (Skorichenko–George)

Comet Skorichenko–George (sometimes spelled Scorichenko–George), formally designated as C/1989 Y1, 1990 VI, and 1989e₁, is a non-periodic comet co-discovered by astronomers Boris Skorichenko and Doug George on December 17, 1989. It has a hyperbolic trajectory around the Sun,^[3] but still weakly bound to it by its barycenter.^[4]

C/1989 Y1 (Skorichenko–George)

Discovery[1][2]
Discovered by	Boris Skoritchenko Douglas B. George
Discovery date	17 December 1989
Designations
Alternative designations	1990 VI 1989e1
Orbital characteristics[3][4]
Epoch	24 February 1990 (JD 2447946.5)
Observation arc	1,008 days (2.76 years)
Number of observations	106
Aphelion	1,188.42 AU
Perihelion	1.569 AU
Semi-major axis	594.994 AU
Eccentricity	0.997363
Orbital period	14,514 years
Inclination	59.3660
Longitude of ascending node	279.998°
Argument of periapsis	137.862°
Last perihelion	11 April 1990
Earth MOID	0.7346 AU
Jupiter MOID	1.8047 AU
Physical characteristics[3]
Comet total magnitude (M1)	5.3
Comet nuclear magnitude (M2)	11.9
Apparent magnitude	9–10 (1990 apparition)

Discovery and observations

It was discovered on December 17, 1989 by Doug George of Kanata (near Ottawa), Ontario, Canada, and Soviet astronomer Boris Skoritchenko (Mezmay, Krasnodar Krai). Skoritchenko was using 8×20 binoculars,^[5] whilst George was using a 16" reflector and had searched for 65 hours^[6]. The comet was magnitude 10.5 in the northern evening sky. It passed its perihelion on April 11, 1990 at a distance of 1.57 AU (235 million km),^[3] and remained visible as a magnitude 9–10 object in the night sky until April 1990

C₂ emission bands were observed in the comet Skorichenko-George. Unlike most comets, Skorichenko–George did not produce a tail.^[7] Its coma remained consistently diffuse, estimated to be around 190,000–290,000 km (120,000–180,000 mi) in diameter.^[7]