C/1932 Y1 (Dodwell–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 byGeorge F. Dodwell
Alexander F. I. Forbes
Discovery siteAdelaide, Australia
Cape Colony, South Africa
Discovery date15–17 December 1932
Designations
1932n[2]
1932 X
Orbital characteristics[3]
Epoch20 January 1933 (JD 2427092.5)
Observation arc63 days
Number of
observations
23
Aphelion80 AU
Perihelion1.131 AU
Semi-major axis40.6 AU
Eccentricity0.97216
Orbital period259 years
Max. orbital speed39.3 km/s
Inclination24.502°
78.589°
Argument of
periapsis
327.357°
Last perihelion30 December 1932
Next perihelion~2191
TJupiter1.320
Earth MOID0.2040 AU
Jupiter MOID0.7849 AU
Physical characteristics
Comet total
magnitude
(M1)
9.1
8.0
(1933 apparition)

Discovery and observations

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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]

References

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  1. ^ a b G. van Biesbroeck (1933). "Comet Notes". Popular Astronomy. 41: 116–117. Bibcode:1933PA.....41..116V.
  2. ^ "Comet Names and Designations". International Comet Quarterly. Retrieved 11 December 2024.
  3. ^ "C/1932 Y1 (Dodwell–Forbes) – JPL Small-Body Database Browser". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 11 December 2024.
  4. ^ C. D. Crommelin (1933). "Comets" (PDF). Monthly Notices of the Royal Astronomical Society. 93 (4): 272–275. doi:10.1093/mnras/93.4.272.
  5. ^ C. H. Schütte (1949). "Two New Families of Comets". Popular Astronomy. 57: 176–182. Bibcode:1949PA.....57..176S.
  6. ^ "Comet families". Oxford Reference. Oxford University Press. Retrieved 11 December 2024.
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