C/1932 Y1 (Dodwell–Forbes)

For other comets discovered by Alexander Forbes, see 37P/Forbes and C/1930 L1 (Forbes).

Comet Dodwell–Forbes, formally designated as C/1932 Y1, is a long-period comet discovered independently by Alexander F. I. Forbes and George F. Dodwell in late 1932. It was Dodwell's only comet discovery, while it was Forbes's third overall.

C/1932 Y1 (Dodwell–Forbes)

Comet Dodwell–Forbes photographed by George van Biesbroeck on 20 January 1933
Discovery[1]
Discovered by	George F. Dodwell Alexander F. I. Forbes
Discovery site	Adelaide, Australia Cape Colony, South Africa
Discovery date	15–17 December 1932
Designations
Alternative designations	1932n[2] 1932 X
Orbital characteristics[3]
Epoch	20 January 1933 (JD 2427092.5)
Observation arc	63 days
Number of observations	23
Aphelion	80 AU
Perihelion	1.131 AU
Semi-major axis	40.6 AU
Eccentricity	0.97216
Orbital period	259 years
Max. orbital speed	39.3 km/s
Inclination	24.502°
Longitude of ascending node	78.589°
Argument of periapsis	327.357°
Last perihelion	30 December 1932
Next perihelion	~2191
TJupiter	1.320
Earth MOID	0.2040 AU
Jupiter MOID	0.7849 AU
Physical characteristics
Comet total magnitude (M1)	9.1
Apparent magnitude	8.0 (1933 apparition)

Discovery and observations

The comet was the brightest of thirteen comets observed in 1932, when George F. Dodwell reported his discovery on 17 December 1932. However, it was soon realized that Alexander F. I. Forbes first spotted the comet from his 8 in (20 cm) reflector two days earlier.^[1] The comet was a 10th-magnitude object at the time of its discovery.^[4]

In 1949, it was speculated that comet Dodwell–Forbes and eight known others were members of a "Neptune-family" of comets based on their similar aphelia (85 AU) and orbital periods ranging between 235 and 300 years.^[5] However, it is now concluded that this comet family did not exist, and their apparent association with Neptune were a result of orbital resonances with Jupiter.^[6]