85D/Boethin
| Discovery | |
|---|---|
| Discovered by | Leo Boethin |
| Discovery date | 4 January 1975 |
| Designations | |
| D/1975 A1 D/1985 T2 | |
| |
| Orbital characteristics | |
| Epoch | 1 June 2007 (JD 2454252.5) |
| Observation arc | 11.07 years (4,042 days) |
| Number of observations | 51 |
| Aphelion | 9.235 AU |
| Perihelion | 1.135 AU |
| Semi-major axis | 5.185 AU |
| Eccentricity | 0.78116 |
| Orbital period | 11.806 years |
| Inclination | 4.295° |
| 359.39° | |
| Argument of periapsis | 37.618° |
| Mean anomaly | 313.19° |
| Last perihelion | 29 July 2020? (unobserved) |
| Next perihelion | 30 November 2031? (lost since 1986) |
| TJupiter | 2.247 |
| Earth MOID | 0.149 AU |
| Physical characteristics | |
Mean radius | 0.7–4.6 km (0.43–2.86 mi) |
| 0.04 (assumed) | |
| 12.0 (1975 apparition) | |
Comet Boethin (officially 85D/Boethin) was a periodic Jupiter-family comet discovered in 1975 by Leo Boethin. It appeared again in January 1986 as expected. Although the comet was next expected at perihelion in April 1997, no observations were reported, and the comet is thought to have disintegrated sometime after it was last observed in March 1986. The comet might have come to perihelion in late July 2020, but the uncertainty in the comet's position is hundreds of millions of km. The old orbit would have the comet next coming to perihelion around November 2031.