12P/Pons–Brooks
12P/Pons–Brooks is a periodic comet with an orbital period of 71 years. Comets with an orbital period of 20–200 years are referred to as Halley-type comets. It is one of the brightest known periodic comets, reaching an absolute visual magnitude of about 5 in its approach to perihelion. Comet Pons-Brooks was conclusively discovered at Marseilles Observatory in July 1812 by Jean-Louis Pons, and on its next appearance in 1883 by William Robert Brooks. There are ancient records of comets that are suspected of having been apparitions of 12P/Pons–Brooks.
12P/Pons-Brooks photographed on 7 March 2024 | |
| Discovery | |
|---|---|
| Discovered by | Jean-Louis Pons William Robert Brooks |
| Discovery date | 12 July 1812 |
| Designations | |
Alternative designations | 1812; 1884 I; 1954 VII; C/1457 A1 ; C/1385 U1 |
| Orbital characteristics | |
| Epoch | 2024-05-10 |
| Aphelion | 33.616 AU |
| Perihelion | 0.78078 AU |
| Semi-major axis | 17.199 AU |
| Eccentricity | 0.95460 |
| Orbital period | 71.32 jyr 69y 10m 30d (perihelion to perihelion) |
| Inclination | 74.191° |
Longitude of ascending node | 255.86° |
| Argument of periapsis | 198.99° |
| Last perihelion | 22 May 1954 25 January 1884 15 September 1812 |
| Next perihelion | 21 April 2024 |
| Earth MOID | 0.176 AU (26.3 million km) |
| Physical characteristics | |
| Dimensions | 34±12 km |
Synodic rotation period | 57±1 hr |
| Comet total magnitude (M1) | 5 |
The next perihelion passage is 21 April 2024, with closest approach to Earth being 1.55 AU (232 million km) on 2 June 2024. The comet is expected to brighten to about apparent magnitude 4.5. The comet nucleus is estimated to be around 30 km in diameter, assuming it was not producing too much dust and gas during the 2020 photometric measurements.
12P/Pons–Brooks is hypothesized to be the parent body of the weak December κ Draconids meteor shower that is active from about 29 November to 13 December.