C/1935 A1 (Johnson)

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

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.

C/1935 A1 (Johnson)

Comet Johnson photographed by George van Biesbroeck shortly after perihelion on 27 February 1935[1]
Discovery[2]
Discovered by	Ernest Leonard Johnson
Discovery site	Union Observatory
Discovery date	7 January 1935
Designations
Alternative designations	1935a[3] 1935 I
Orbital characteristics[4]
Epoch	28 February 1935 (JD 2427861.5)
Observation arc	68 days
Number of observations	34
Aphelion	~190 AU
Perihelion	0.811 AU
Semi-major axis	93.21 AU
Eccentricity	0.99130
Orbital period	~900 years
Inclination	65.424°
Longitude of ascending node	92.445°
Argument of periapsis	18.399°
Mean anomaly	0.002°
Last perihelion	26 February 1935
Next perihelion	~2830s
TJupiter	0.519
Earth MOID	0.149 AU
Jupiter MOID	2.175 AU
Physical characteristics[5]
Comet total magnitude (M1)	9.5
Comet nuclear magnitude (M2)	12.5
Apparent magnitude	8.4 (1935 apparition)

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.^[6][7] 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.^[5]