75D/Kohoutek

For other comets of the same name, see Comet Kohoutek (disambiguation).

75D/Kohoutek is a short-period comet discovered in February 1975, by Luboš Kohoutek. Even on the discovery plate the comet was only apparent magnitude 14.^[4] Assuming the comet has not disintegrated the 2020-2021 perihelion passage is only expected to peak around apparent magnitude 20.

75D/Kohoutek

Image of the orbit of the 75D/Kohoutek comet
Discovery
Discovered by	Luboš Kohoutek
Discovery site	Hamburg-Bergedorf Observatory
Discovery date	9 February 1975
Designations
MPC designation	D/1975 C1 D/1980 P1
Alternative designations	1975 III, 1981 IX, 1987 XXVII 1975c, 1980j, 1986k
Orbital characteristics[1][2]
Epoch	25 February 2023 (JD 2460000.5)
Observation arc	13.27 years
Number of observations	81
Aphelion	5.3 AU
Perihelion	1.773 AU
Semi-major axis	3.538 AU
Eccentricity	0.49889
Orbital period	~6.66 years
Inclination	5.92°
Longitude of ascending node	269.6°
Argument of periapsis	175.5°
Mean anomaly	106.6°
Last perihelion	7 March 2021?[3] (last seen 1988)
Next perihelion	2 November 2027?[3] (Predicted)
TJupiter	2.894
Earth MOID	0.8 AU
Physical characteristics[1]
Mean diameter	4.6 km (2.9 mi)
Comet total magnitude (M1)	10.5
Comet nuclear magnitude (M2)	14.5
Apparent magnitude	14.0 (1975 apparition)

Not to be confused with the much better-known C/1973 E1 (Kohoutek), 75D is a repeat visitor to the inner Solar System, with a period of about seven years. It was placed on the discovery orbit when it passed 0.143 AU (21.4 million km) from Jupiter on 28 July 1972.^[4][1] Apparitions have been dim, with the brightest being in 1988 at about apparent magnitude 13.^[4] It was not seen in 1994, 2000, 2007, nor on its last predicted return in 2014. The comet has been estimated to be 4.6 km (2.9 mi) in diameter.^[1]

This comet was last observed by Mauna Kea on 19 May 1988.^[2] The Minor Planet Center has given the comet a "D/" designation as the comet is believed to be lost.^[2][5] The comet is calculated to come to opposition in October 2020 in the constellation of Pisces.^{[needs update]}

See also

• List of numbered comets