100P/Hartley

Observational history

Discovery

Malcolm Hartley discovered the comet from CCD images taken from the UK Schmidt Telescope in Australia on 13 June 1985. At the time, the comet was a 16th-magnitude object within the constellation Virgo, with a prominent tail extending about 1 arcminute towards the southeast. Despite the discovery announcement, Hartley remained the comet's only observer for the next three weeks.

Follow-up observations

An additional observation by Hartley on 10 July 1985 has allowed Brian G. Marsden to compute the elliptical orbit of the comet for the first time, revealing that it was a short-period comet with a 5.66-year orbit around the Sun. James B. Gibson obtained the only known Northern hemisphere observations of the comet during its first apparition on 27–29 July 1985. It was last detected by Alan C. Gilmore on 14 August 1985.

The small number of observations during its 1985 apparition has caused uncertainties in revising its orbit that it was almost considered lost. It was successfully recovered by David H. Levy, Carolyn and Eugene Shoemaker on the night of 12 March 1991, about 16 degrees from its predicted position. Marsden later noted that the comet made a close encounter with Jupiter on February 1988, passing within 0.36 AU from the giant planet.

References

Notes

Citations

| access-date= 2023-04-29 }} (JPL#38/Soln.date: 20 August 2022)

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| access-date= 2025-05-22 }}

| chapter-url= https://physics.ucf.edu/~yfernandez/papers/comets2chapter/comets2reprint.pdf

| access-date= 2014-11-01 }}

Bibliography

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