110P/Hartley
Periodic comet
From Wikipedia, the free encyclopedia
Comet Hartley 3 is a periodic comet with a six-year orbit around the Sun. It is one of ten comets discovered by Australian astronomer, Malcolm Hartley.
P/1993 M1
Comet Hartley 3 imaged from the Zwicky Transient Facility on 20 November 2021 | |
| Discovery[1] | |
|---|---|
| Discovered by | Malcolm Hartley |
| Discovery site | UK Schmidt Telescope |
| Discovery date | 19 February 1988 |
| Designations | |
| P/1988 D1 P/1993 M1 | |
| |
| Orbital characteristics[2][3] | |
| Epoch | 25 February 2023 (JD 2460000.5) |
| Observation arc | 35.23 years |
| Number of observations | 3,998 |
| Aphelion | 4.752 AU |
| Perihelion | 2.455 AU |
| Semi-major axis | 3.604 AU |
| Eccentricity | 0.31870 |
| Orbital period | 6.841 years |
| Inclination | 11.705° |
| 287.52° | |
| Argument of periapsis | 167.46° |
| Mean anomaly | 71.255° |
| Last perihelion | 18 October 2021 |
| Next perihelion | 28 August 2028[4] |
| TJupiter | 2.990 |
| Earth MOID | 1.483 AU |
| Jupiter MOID | 0.478 AU |
| Physical characteristics[2][5][6] | |
Mean radius | 2.31±0.03 km |
Mean density | 0.13±0.02 g/cm3 |
| 10.153±0.001 hours | |
| (V–R) = 0.67±0.09 | |
| Comet total magnitude (M1) | 4.3 |
| Comet nuclear magnitude (M2) | 13.3 |
Observational history
Discovery
The comet appeared as a weak trail at magnitude 16.5 on the edge of its discovery plates, which were taken from the UK Schmidt Telescope of the Siding Spring Observatory.[7] By 22 February, Hartley confirmed his discovery using the same telescope, and found a tail about 10 arcminutes in length.[1] From the Palomar Observatory, both Carolyn and Eugene Shoemaker found two precovery images of the comet about 4.8 hours before its official discovery.[8] By then, it was determined that Hartley's find is definitely a short-period comet.[8]
Follow-up observations
Six observatories around the globe made observations of Hartley 3 in March 1988, including those made by Tsutomu Seki, Robert H. McNaught, James V. Scotti, and David H. Levy.[7] By April 1988, revised orbital calculations by Brian G. Marsden indicated that the comet completes an elliptical orbit once every 6.85 years.[9]
Hartley 3 was successfully recovered by James V. Scotti using the Spacewatch telescope of the Kitt Peak Observatory on 23 June 1993.[10]
Physical characteristics
Observations by the Hubble Space Telescope in 2004 and 2011 revealed that the effective radius of its nucleus is around 2.15±0.04 km and a rotation period of 9.4±1.0 hours.[11][12] Later ground observations from Pan-STARRS and other sky surveys revised the radius and rotation periods to 2.31±0.03 km and 10.153±0.001 hours, respectively.[5]