C/1955 O1 (Honda)

For other comets of the same name, see Comet Honda.

C/1955 O1 (Honda) is a hyperbolic comet that made its closest approach to Earth on 18 August 1955, at a distance of 0.272 AU (40.7 million km).^[4] It is one of several comets discovered by Japanese astronomer, Minoru Honda.

C/1955 O1 (Honda)

Honda's Comet photographed by Paolo Maffei from Italy on 23 August 1955.[1]
Discovery[2]
Discovered by	Minoru Honda
Discovery site	Kurashiki, Japan
Discovery date	29 July 1955
Designations
Alternative designations	1955 V, 1955g[3]
Orbital characteristics[4]
Epoch	9 September 1955 (JD 2435359.5)
Observation arc	96 days
Number of observations	43
Perihelion	0.885 AU
Eccentricity	1.00111
Inclination	107.52°
Longitude of ascending node	339.42°
Argument of periapsis	348.20°
Mean anomaly	0.002°
Last perihelion	4 August 1955
Earth MOID	0.114 AU
Jupiter MOID	3.233 AU
Physical characteristics[5][6]
Mean radius	1.04 km (0.65 mi)[a]
Comet total magnitude (M1)	6.8
Comet nuclear magnitude (M2)	11.5
Apparent magnitude	5.0 (1955 apparition)

Observational history

Discovery

Minoru Honda found his seventh comet overall on the night of 29 July 1955,^[2] as a diffuse 8th-magnitude object within the constellation Orion.^[b]

Follow-up observations

The comet barely reached naked eye visibility starting on 24 August 1955.^[7] By September 1955, it reached peak brightness at magnitude 5.0, believed to be caused by a large outburst that was initially thought to be the comet's fragmentation/splitting event.^[8][9]

It was last seen by Max Beyer on 20 November 1955,^[10] as a 13th-magnitude object within the constellation Hercules.^[6] Elizabeth Roemer and Hamilton Jeffers attempted to recover the comet from the Lick Observatory between February and March 1956 but failed to locate it.^[11]