C/1935 A1 (Johnson)

C/1935 A1 (Johnson)
Comet Johnson photographed by George van Biesbroeck shortly after perihelion on 27 February 1935
Discovery
Discovered byErnest Leonard Johnson
Discovery siteUnion Observatory
Discovery date7 January 1935
Designations
1935a
1935 I
Orbital characteristics
Epoch28 February 1935 (JD 2427861.5)
Observation arc68 days
Number of
observations		34
Aphelion~190 AU
Perihelion0.811 AU
Semi-major axis93.21 AU
Eccentricity0.99130
Orbital period~900 years
Inclination65.424°
92.445°
Argument of
periapsis		18.399°
Mean anomaly0.002°
Last perihelion26 February 1935
Next perihelion~2830s
TJupiter0.519
Earth MOID0.149 AU
Jupiter MOID2.175 AU
Physical characteristics
Comet total
magnitude (M1)		9.5
Comet nuclear
magnitude (M2)		12.5
8.4
(1935 apparition)

Johnson's Comet, formally designated as C/1935 A1, is a long-period comet with a 900-year orbit around the Sun. It is the first of four comets discovered by South African astronomer, Ernest Leonard Johnson.

Orbit

Between February and March 1936, Allan D. Maxwell calculated that the comet had an orbital period of 750 years, later revised to 896 years. This is a follow-up to the preliminary parabolic solutions that were first calculated by J. P. Möller and H. Q. Rassumen a year prior.

References

  1. ↑ G. van Biesbroeck (1935). "Comet Notes". Popular Astronomy. 43: 254–255. Bibcode:1935PA.....43..254V.
  2. ↑ "First Comet of 1935" (PDF). Nature. 135: 115. 1935. doi:10.1038/135115c0.
  3. ↑ "Comet Names and Designations". International Comet Quarterly. Retrieved 27 January 2025.
  4. ↑ "C/1935 A1 (Johnson) – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 27 January 2025.
  5. 1 2 G. W. Kronk (2009). Cometography: A Catalog of Comets. Vol. 4: 1933–1959. Cambridge University Press. pp. 20–25. ISBN 978-0-521-58507-1.
  6. ↑ A. D. Maxwell (1936). "The Orbit of Comet 1935a". Astronomical Journal. 45 (1041): 49–54. Bibcode:1936AJ.....45...49M. doi:10.1086/105322.
  7. ↑ A. D. Maxwell (1937). "Elements and Ephemeris of Comet 1935a (Johnson)". Publications of the Observatory of the University of Michigan. 6 (7): 63–65. Bibcode:1937POMic...6...63M.