C/1937 P1 (Hubble)
The only comet discovered by Edwin Hubble.
C/1937 P1 (Hubble), commonly called Comet Hubble, is a long-period comet that takes about 600 years to orbit the Sun. It holds the distinction of being the first and only comet discovered by the astronomer Edwin Hubble.
The comet was already moving away from the Sun when it was first observed in August 1937, appearing as a faint 13.5-magnitude object in the constellation Aquarius. Initial reports described it as diffuse, lacking a clear central condensation or nucleus. It was the fourth comet found in 1937. Subsequent observations proved challenging because the comet remained close to the Sun in the sky and low above the horizon. Although it stayed faint throughout its visibility, many observations were carried out at the Union Observatory in Johannesburg, South Africa. By 7 September 1937, the comet had dimmed to magnitude 14.5, as recorded by the Crossley telescope. The last sighting of C/1937 P1 was on 28 October 1937.
The first orbital calculations were performed by L. E. Cunningham and A. D. Maxwell on 9 August 1937, and by 1938 the comet was confirmed to follow an elliptical orbit. For a time, it was briefly thought to be the same object as the then-lost periodic comet 9P/Tempel. Further calculations in 1952 revealed that the comet had reached perihelion on 14 November 1936, about nine months before its discovery, and that its orbit is long-period, lasting roughly 600 years.
Quick Facts
- Discovery Ref
- IAUC_673
- Discoverer
- Edwin P. Hubble
- Discovery Site
- Mount Wilson Observatory
- Discovery Date
- 4 August 1937
- Designations
- 1936 V, 1937gICQ1
- Orbit Ref
- jpldata
- Epoch
- 8 November 1936 (JD 2428480.5)
- Observation Arc
- 85 days
- Obs
- 58
- Aphelion
- ~140 AU
- Perihelion
- 1.954 AU
- Semimajor
- 71.039 AU
Facts from the source article.
Lore & Background
Comet Hubble was first spotted in August 1937 as a magnitude 13.5 object in the constellation Aquarius, already on its outbound flight. Initially reported as diffuse without a central condensation or nucleus, it was the fourth comet discovered in 1937. Follow-up observations were difficult due to its apparent close proximity to the Sun and low altitude over the horizon. Despite being faint throughout its visibility, numerous observations were conducted at the Union Observatory in Johannesburg, South Africa. By 7 September 1937, the comet had faded to apparent magnitude 14.5 as reported from the Crossley telescope. It was last seen on 28 October 1937.
Reader's Guide
The first orbital calculations were made by L. E. Cunningham and A. D. Maxwell on 9 August 1937, and the comet was later known to have an elliptical orbit by 1938. At one point, it was briefly considered to be the same object as 9P/Tempel, which at the time was considered lost. Further calculations in 1952 showed that the comet came to perihelion on 14 November 1936, about nine months prior to discovery, and has a long-periodic orbit of about 600 years. Its significance lies in being the sole cometary discovery of Edwin Hubble, a renowned astronomer, and in the historical confusion with the lost periodic comet 9P/Tempel. The comet's faintness and challenging observing conditions underscore the difficulties of early 20th-century comet detection.
Did You Know?
- Comet Hubble is the first and only comet discovered by Edwin Hubble.
- The comet was briefly considered to be the same object as the lost comet 9P/Tempel.
Frequently Asked Questions
What is C/1937 P1 (Hubble)?
It is a long-period comet whose full orbit around the Sun takes roughly 600 years, making it a rare visitor to the inner solar system. It is best known as the only comet ever credited to the discovery of Edwin Hubble.
How was C/1937 P1 (Hubble) discovered?
Edwin Hubble spotted it in August 1937 as a faint 13.5-magnitude smudge in the constellation Aquarius, at which point it was already heading back out from the Sun. It turned out to be the fourth comet identified that calendar year.
Why is C/1937 P1 (Hubble) considered unique among named comets?
It is the sole comet in the historical record discovered by Edwin Hubble, the astronomer far more widely celebrated for his work on galaxies and cosmic expansion. No other comet carries his name, making this a one-of-a-kind distinction.
What did C/1937 P1 (Hubble) look like to early observers?
Initial reports described it as a diffuse, hazy patch with no clearly visible nucleus or central condensation. Follow-up tracking was hampered because the comet lingered in the Sun's glare for much of its observable window.
When did C/1937 P1 (Hubble) reach perihelion?
Its closest approach to the Sun occurred on 14 November 1936, well before Hubble first saw it in August 1937. That timing explains why the comet was already receding and fading at the moment of discovery.
More in Named Comets, Part 3 1-24
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