12P/Pons–Brooks is a periodic comet with an orbital period of 71 years. It fits the classical definition of a Halley-type comet with an orbital period between 20 and 200 years, and is also one of the brightest known periodic comets, reaching an absolute visual magnitude ~5 in its approach to perihelion. Comet Pons-Brooks was discovered at Marseilles Observatory in July 1812 by Jean-Louis Pons, and then later recovered in 1883 by William Robert Brooks.
The next perihelion passage is 21 April 2024, with closest approach to Earth being 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 photometry.
12P/Pons–Brooks may be the parent body of the weak December κ-Draconids meteor shower that is active from about November 29 to December 13.
Observational history
Before 1812
Comet 12P/Pons-Brooks has been identified as a comet observed in 1385 and in 1457. The 1385 apparition was very favourable and the comet was recorded by the Chinese in Ming Shilu and was also mentioned in some European sources. A comet observed by Paolo dal Pozzo Toscanelli in January 1457 and also mentioned in Chinese sources is also identified as comet 12P/Pons-Brooks. In both apparitions the comet had a magnitude of 3 or brighter, not accounting for possible outbursts. It is possible that it was also a comet recorded in Chinese sources in September 245 CE.
The comet has been suggested by So-Yeon Park and Jong-Chul Chae that was also the comets recorded in Asian sources in 1313 and 1668. However, Meyer et al argue that in the 1313 apparition, the comet would have been difficult to observe, being dim and close to the Sun, while the suggested position in Gemini contradicts the calculated location of comet Pons-Brooks in Aries. The March 1668 comet described by Koreans is probably the bright sungrazing comet observed by Europeans, whose orbit is no way compatible with that of comet 12P/Pons-Brooks.
1812 discovery
Comet 12P/Pons–Brooks was discovered on July 12, 1812, by Jean-Louis Pons. Independently, this comet was later found by Vincent Wisniewski on August 1, and Alexis Bouvard on August 2 the same year. The comet was spotted with the naked eye on 13 August and by the end of the month a tail measuring 2 degrees in length was reported. Shortly after its initial discovery it was found to have an orbital period of about 70 years with an error of about 5 years. Johann Franz Encke determined a definitive orbit with a period of 70.68 years. This orbit was used to generate an ephemeris for the 1883-4 return.
1884
On 2 September 1883 a (faint) comet was accidentally discovered by William Robert Brooks and later identified with the comet of 1812. An outburst was observed on 21-23 September 1883, as the comet brightened from magnitude 10–11 to 8–8.5 and its appearance changed from diffuse to star-like. The comet became visible with naked eye in 20 November and brightened up to a magnitude of 3. The comet was reported to experience outbursts on January 1 and January 19. This year it traveled from Scheat and Markab in western Pegasus, 13 January 1884; southward (through Pisces) to reach perihelion below Iota and Beta Ceti (~RA 0h, Dec. -10°) around 24 January. It was last seen in June 1884.
1954
The comet was recovered on 20 June 1953 when it was 4.5 AU from the Sun. The comet outburst from magnitude 18 to magnitude 13 on 1 July 1953. Another outburst occurred in March 1954, the fourth observed in that apparition. On April 23, the comet had an estimated magnitude of 6.4 and its tail was half a degree long. Pons–Brooks came to perihelion on May 22, 1954 when it was 1.7 AU from Earth. After perihelion it became better visible from the south hemisphere. It was last observed on 4 September 1954 when it was 1.9 AU from the Sun. On 10 December 1954, the meteor stream of comet Pons–Brooks passed about from Earth, resulting in potential meteors impacting Earth`s atmosphere at relative velocity 45 km/s.