94P/Russell

94P/Russell 4
Comet Russell 4 imaged by Kevin Heider on 19 February 2010 while it was 2.2 AU from the Sun.
Discovery
Discovered byKenneth S. Russell
Discovery siteSiding Spring Observatory
Discovery date7 March 1984
Designations
P/1984 E1, P/1989 X2
  • Russell 4
  • 1984 I, 1990 XI
  • 1984d, 1989g1
Orbital characteristics
Epoch21 November 2025 (JD 2461000.5)
Observation arc75.27 years
Earliest precovery date10 May 1950
Number of
observations		2,242
Aphelion4.795 AU
Perihelion2.225 AU
Semi-major axis3.509 AU
Eccentricity0.36616
Orbital period6.575 yr
Inclination6.187°
70.842°
Argument of
periapsis		92.377°
Mean anomaly137.10°
Last perihelion21 May 2023
Next perihelion17 December 2029
TJupiter3.003
Earth MOID1.251 AU
Jupiter MOID0.462 AU
Physical characteristics
Mean radius
2.6 km (1.6 mi)
20.7 hours
0.043±0.007
(V–R) = 0.62±0.05
Comet total
magnitude (M1)		13.4

94P/Russell, also known as Comet Russell 4, is an Encke-type comet with a 6.58-year orbit around the Sun. It is the fifth comet discovered overall by Australian astronomer, Kenneth S. Russell.

Observational history

It was discovered by Kenneth S. Russell on photographic plates taken by M. Hawkins on March 7, 1984. In the discovery images, Russell estimated that the comet had an apparent magnitude of 13 and a noticeable tail of 5 arcminutes. In the year of discovery, the comet had come to perihelion in January 1984.

Orbit

With an aphelion of 4.7 AU (700 million km), comet 94P currently has an orbit contained completely inside of the orbit of Jupiter. It fits the definition of an Encke-type comet with (TJupiter > 3; a < aJupiter).

Physical characteristics

In July 1995, 94P was estimated to have a radius of about 2.6 km (1.6 mi) with an absolute magnitude (H) of 15.1. It may have a very elongated nucleus with an axial ratio of a/b ≥ 3. It is determined that it has a rotation period of 20.7 hours.

Notes

  1. ↑ Observation arc from the Minor Planet Center database covering dates from 10 May 1950 until 16 August 2025.
  2. ↑ Kenneth S. Russell's prior comet discoveries from 1979 to 1983 were; 83D/Russell, C/1980 R1, 89P/Russell, and 91P/Russell, respectively.

References

  1. 1 2 K. S. Russell; M. Hawkins (9 March 1984). B. G. Marsden (ed.). "Comet Russell (1984d)". IAU Circular. 3926 (1). Bibcode:1984IAUC.3926....1R.
  2. ↑ "Periodic Comet Names and Designations". Planetary Data System: Small Body Node. NASA. Retrieved 4 September 2026.
  3. 1 2 3 4 "94P/Russell 4 – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 19 February 2010.
  4. ↑ "94P/Russell Orbit". Minor Planet Center. Retrieved 17 June 2014.
  5. ↑ "Horizons Batch for 94P/Russell 4 (90000915) on 2029-Dec-17" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 29 April 2023. (JPL#74/Soln.date: 2023-Jul-05)
  6. 1 2 3 C. Snodgrass; S. C. Lowry; A. Fitzsimmons (2007). "Optical observations of 23 distant Jupiter Family Comets, including 36P/Whipple at multiple phase angles" (PDF). Monthly Notices of the Royal Astronomical Society. 385 (2): 737–756. arXiv:0712.4204. Bibcode:2008MNRAS.385..737S. doi:10.1111/j.1365-2966.2008.12900.x. S2CID 55536237.
  7. 1 2 B. E. A. Mueller; N. H. Samarasinha (2018). "Further Investigation of Changes in Cometary Rotation". The Astronomical Journal. 156 (3): 107–114. arXiv:1806.11158. Bibcode:2018AJ....156..107M. doi:10.3847/1538-3881/aad0a1.
  8. ↑ M. M. Knight; R. Kokotanekova; N. H. Samarasinha (2024). "Physical and Surface Properties of Comet Nuclei from Remote Observations". In K. J. Meech (ed.). Comets III. University of Arizona Press. pp. 361–404. arXiv:2304.09309. JSTOR jj.21819446.18.
  9. ↑ Kronk, Gary W. "94P/Russell 4". Retrieved 19 February 2010. (Cometography Home Page)
  10. ↑ Seiichi Yoshida (25 October 2008). "94P/Russell 4". Seiichi Yoshida's Comet Catalog. Retrieved 19 February 2010.