75D/Kohoutek
DiscovererLuboš Kohoutek
Discovery siteHamburg-Bergedorf Observatory
Discovery date9 February 1975
Mpc nameD/1975 C1, D/1980 P1
Designations
  • 1975 III, 1981 IX
  • 1987 XXVII
  • 1975c, 1980j, 1986k
Epoch25 February 2023 (JD 2460000.5)
Observation arc13.27 years
(Not observed in 38 years)[1]
Obs104
Perihelion1.77 AU
Aphelion5.3 AU
Semimajor3.54 AU
Eccentricity0.499
Period6.7 years
Inclination5.92°
Asc node269.6°
Arg peri175.5°
Mean106.6°
Tjup2.894
Earth moid0.8 AU
Mean radius1.7 km (1.1 mi)[2]
M 110.5
M 214.5
Magnitude14.0
(1975 apparition)
Last p7 March 2021?[3]
(last seen 1988)
Next p2 November 2027?[4][3][5]
(assumed)

75D/Kohoutek is a periodic comet discovered in February 1975, by Luboš Kohoutek. Even on the discovery plate the comet was only apparent magnitude 14.[6] The comet was last observed in 1988 and has not been observed in 38 years.

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 astronomical units from Jupiter on 28 July 1972.[6][7] Apparitions have been dim, with the brightest being in 1988 at about apparent magnitude 13.[6] It was not seen in 1994, 2000, 2007, 2014, or 2021. The comet has been estimated to be 4.6 km (2.9 mi) in diameter.[7]

This comet was last observed by Mauna Kea on 19 May 1988.[1] The Minor Planet Center has given the comet a "D/" designation as the comet is believed to be lost.[1][8]

In August 2026 the comet is calculated to come to opposition in the constellation of Aquarius at around apparent magnitude 19.5.[9] In late January 2028 it may come to opposition in the constellation of Cancer at around apparent magnitude 16.[10]

See also

References

  1. ^ "75D/Kohoutek Orbit". Minor Planet Center. Retrieved 30 October 2014.
  2. ^ M. J. S. Belton (2014). "The Size-distribution of Scattered Disk TNOs from that of JFCs between 0.2 and 15-km effective radius". Icarus. 231 (1): 168–182. arXiv:1312.1424. Bibcode:2014Icar..231..168B. doi:10.1016/j.icarus.2013.12.001
  3. ^ S. Yoshida (31 October 2021). "75D/Kohoutek". www.aerith.net. Retrieved 16 March 2025.
  4. ^ "Horizons Batch for 75D/Kohoutek (90000826) on 2027-Nov-02" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 2026-04-05. (JPL#J873/16/Soln.date: 2000-Sep-07)
  5. ^ K. Kinoshita (1998-03-09). "75D/Kohoutek past, present and future orbital elements". Comet Orbit. Retrieved 2026-04-10.
  6. ^ G. W. Kronk. "75P/Kohoutek". Cometography.com. Archived from the original on 25 August 2009. Retrieved 30 October 2014.
  7. ^ "75D/Kohoutek – JPL Small-Body Database Lookup". Jet Propulsion Laboratory. Retrieved 16 March 2025.
  8. ^ "Cometary Designation System". Minor Planet Center. Retrieved 17 June 2015.
  9. ^ "Horizons Batch for 75D/Kohoutek (90000826) in August 2026". JPL Horizons. Retrieved 2026-04-05.
  10. ^ "Horizons Batch for 75D/Kohoutek (90000826) in January 2028". JPL Horizons. Retrieved 2026-04-08.