C/1861 G1 (Thatcher)
|Discovered by||A. E. Thatcher|
|Discovery date||April 5, 1861|
|Orbital characteristics A|
(May 25, 1861)
|Orbit type||Long period comet|
|Semi-major axis||55.6 AU|
|Orbital period||415 a|
|Next perihelion||2283 ±5|
Comet C/1861 G1 (Thatcher) is a long-period comet with roughly a 415-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. 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 1861-May-05 and last came to perihelion (closest approach to the Sun) on 1861-Jun-03.
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, it should receive the P/ designation.
The comet is the parent body of the April Lyrids meteor shower.
- "JPL Small-Body Database Browser: C/1861 G1 (Thatcher)". Jet Propulsion Laboratory. Retrieved 2012-04-21.
- Horizons output. "Observer Table for Comet C/1861 G1 (Thatcher)". Retrieved 2020-08-07. (Observer Location:@sun Perihelion occurs when deldot flips from negative to positive)
- 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.