Comet C/1861 G1 (Thatcher) is a long-period comet with roughly a 422-year orbit that is expected to return around 2283. It was discovered by A. E. Thatcher. It is responsible for the April Lyrid meteor shower.[4] Carl Wilhelm Baeker also independently found this comet. The comet passed about 0.335 AU (50.1 million km; 31.1 million mi) from the Earth on 5 May 1861 and last came to perihelion (closest approach to the Sun) on 3 June 1861.[3]
| Discovery | |
|---|---|
| Discovered by | A. E. Thatcher |
| Discovery date | April 5, 1861 |
| Designations | |
| 1861 I | |
| Orbital characteristics[1][2][3] | |
| Observation arc | 149 days |
| Number of observations | 187 |
| Orbit type | Long period comet |
| Aphelion | 112 AU (beyond Eris) |
| Perihelion | 0.921 AU (1861) 0.917 AU (2283) |
| Semi-major axis | 56.3 AU |
| Eccentricity | 0.983 |
| Orbital period | 422 yr (barycentric) |
| Inclination | 79.77° |
| Last perihelion | 1861-Jun-03 |
| Next perihelion | 2283 ±5 |
C/1861 G1 is listed as a long-period "non-periodic comet" because it has not yet been observed at two perihelion passages. When it is seen to come back around 2283,[2] it should receive the P/ designation.
The comet is the parent body of the April Lyrids meteor shower.
See also
edit- C/1861 J1 – Great comet of 1861
- 153P/Ikeya–Zhang – periodic comet with a 366-year orbit
References
edit- ^ Horizons output. "Barycentric Osculating Orbital Elements for Thatcher (C/1861 G1) at epoch 1900". Retrieved 2023-08-26. (Solution using the Solar System's barycenter (Sun+Jupiter). Select Ephemeris Type:Elements and Center:@0)
(PR= 1.54E+05 / 365.25 = 422 years) - ^ a b Horizons output. "2283 Perihelion for Comet C/1861 G1 (Thatcher)". Retrieved 2020-08-07. (Observer Location:@sun Perihelion occurs when deldot flips from negative to positive)
- ^ a b "JPL Small-Body Database Browser: C/1861 G1 (Thatcher)". Jet Propulsion Laboratory. Retrieved 2012-04-21.
- ^ Arter, T. R.; Williams, I. P. (1997). "The mean orbit of the April Lyrids". Monthly Notices of the Royal Astronomical Society. 289 (3): 721–728. Bibcode:1997MNRAS.289..721A. doi:10.1093/mnras/289.3.721.
External links
edit- Thatcher at the JPL Small-Body Database
