21P/Giacobini–Zinner
< 21P
Comet Giacobini–Zinner photographed from Moscow, Russia on 9 September 2018. | |
| Discovery | |
|---|---|
| Discovered by | Michel Giacobini Ernst Zinner |
| Discovery date | 20 December 1900 23 October 1913 |
| Designations | |
| P/1900 Y1 P/1913 U1 | |
| 1900 III; 1913 V; 1926 VI; 1933 III; 1940 I; 1946 V; 1959 VIII; 1966 I; 1972 VI; 1979 III; 1985 XIII; 1992 IX | |
| Orbital characteristics | |
| Epoch | 13 November 2017 (JD 2458070.5) |
| Observation arc | 4,922 days (13.48 years) |
| Number of observations | 1,993 |
| Aphelion | 5.987 AU |
| Perihelion | 1.013 AU/2192480km (2031 aparition) |
| Semi-major axis | 3.492 AU |
| Eccentricity | 0.71047 |
| Orbital period | 6.549 years |
| Inclination | 32.002° |
| 195.40° | |
| Argument of periapsis | 172.81° |
| Last perihelion | 25 March 2025 |
| Next perihelion | 8 October 2031 |
| TJupiter | 2.465 |
| Earth MOID | 0.018 AU |
| Jupiter MOID | 0.248 AU |
| Physical characteristics | |
| Dimensions | 2.0 km (1.2 mi) |
| 7.39±0.01 hours | |
| Comet total magnitude (M1) | 13.2 |
Comet Giacobini–Zinner (officially designated as 21P/Giacobini–Zinner) is a periodic comet in the Solar System. It was discovered by Michel Giacobini, who observed it in the constellation of Aquarius on 20 December 1900. It was recovered two orbits later by Ernst Zinner, while he was observing variable stars near Beta Scuti on 23 October 1913.