Comet 87P/Bus is a periodic comet with an orbital period of 6.5 years. It fits the definition of an Encke-type comet with (TJupiter > 3; a < aJupiter). It was discovered by Schelte J. Bus in 1981 on a plate taken with the 1.2m UK Schmidt telescope at Siding Spring, Australia. The discovery was announced in IAU Circular 3578 on March 4, 1981.[5] It has been observed on each of its subsequent apparitions, most recently in 2020.[6]

87P/Bus
Discovery
Discovered bySchelte J. Bus
Discovery date1981
Designations
Bus/1981b; Bus/1981 XI;
Orbital characteristics
EpochMarch 6, 2006
Aphelion4.798 AU
Perihelion2.174 AU
Semi-major axis3.486 AU
Eccentricity0.3764
Orbital period6.509 a
Inclination2.5768°
Last perihelionMay 9, 2020[1]
December 19, 2013[2][3]
July 7, 2007
Next perihelion2029-Jun-07[4]

Its nucleus is estimated to have an effective radius of 0.27 ± 0.01 kilometers and to be elongated, with an a/b ratio greater than 2.2. Its rotational period is estimated to be 32 ± 9 hours.[7]

A close approach to Jupiter on 13 May 1952, at a distance of 0.0668 AU, lowered the orbital period from 12.46 years and the perihelion distance from 4.43 AU to 6.43 years and 2.13 AU respectively. Another close approach to Jupiter on 24 February 2023, at a distance of 0.182 AU, raised the perihelion to 3.62 AU and the orbital period to 9.58 years.[8]

References

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  1. ^ "87P/Bus Orbit". Minor Planet Center. Retrieved 2014-06-16.
  2. ^ Syuichi Nakano (2010-04-29). "87P/Bus (NK 1931)". OAA Computing and Minor Planet Sections. Retrieved 2012-02-18.
  3. ^ 87P past, present and future orbital elements
  4. ^ "Horizons Batch for 87P/Bus (90000883) on 2029-Jun-07" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 2022-06-27. (JPL#K203/18 Soln.date: 2020-Sep-28)
  5. ^ Bus, S. J.; Russell, K. S. (1 March 1981). "Comet Bus (1981b)". International Astronomical Union Circular. 3578: 1. ISSN 0081-0304.
  6. ^ "87/P Bus". Seiichi Yoshida. Retrieved 15 May 2015.
  7. ^ Lamy, P. L.; Toth, I.; Weaver, H. A.; A'Hearn, M. F.; Jorda, L. (11 April 2011). "Properties of the nuclei and comae of 10 ecliptic comets from Hubble Space Telescope multi-orbit observations★: HST observations of 10 ecliptic comets". Monthly Notices of the Royal Astronomical Society. 412 (3): 1573–1590. doi:10.1111/j.1365-2966.2010.17934.x.
  8. ^ Kinoshita, Kazuo (2014-02-13). "87P/Bus past, present and future orbital elements". Comet Orbit. Retrieved 2024-11-13.{{cite web}}: CS1 maint: url-status (link)
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88P/Howell