Comets in 2023

periodic comet

long period comet

long period comet

Comet Hartley 2, designated as 103P/Hartley by the Minor Planet Center, is a small periodic comet with an orbital period of 6.48 years. It was discovered by Malcolm Hartley in 1986 at the Schmidt Telescope Unit, Siding Spring Observatory, Australia. Its diameter is estimated to be

Comet Grigg–Skjellerup (formally designated 26P/Grigg–Skjellerup) is a periodic comet. It was visited by the Giotto probe in July 1992. The spacecraft came as close as 200 km, but could not take pictures because some instruments were damaged from its encounter with Halley's Comet. The comet last came to perihelion (closest approach to the Sun) on 25 December 2023, but was 1.8 AU from Earth and only 31 degrees from the Sun.

39P/Oterma is a currently inactive periodic comet with an orbital period of nearly 20 years that stays outside the orbit of Jupiter. The nucleus has a diameter around 4–5 km. It was last observed in August 2021 and came to perihelion in July 2023 while 1.2 AU from Jupiter. It made a moderately close approach to Jupiter in January 2025 and will next come to perihelion in July 2042 at distance of 5.9 AU from the Sun. Opposition has occurred on 11 November 2023.

comet

Comet 96P/Machholz, also known as Machholz 1 is a periodic sunskirting comet discovered on 12 May 1986, by amateur astronomer Donald Machholz on Loma Prieta peak, in central California using binoculars. On 6 June 1986, 96P/Machholz passed from the Earth. 96P/Machholz last came to perihelion on January 31, 2023. The comet has an estimated diameter of around .

147P/Kushida–Muramatsu is a quasi-Hilda comet discovered in 1993 by Japanese astronomers Yoshio Kushida and Osamu Muramatsu.

322P/SOHO is the first periodic comet to be discovered using the automated telescopes of the Solar and Heliospheric Observatory (SOHO) spacecraft, and second to be given a numbered designation, after 321P/SOHO. At perihelion, it is six times closer to the Sun than the planet Mercury.

{| class=wikitable style="text-align:center; font-size:11px; float:right; margin:2px" |- bgcolor= style="font-size: smaller;" | colspan="8" style="text-align:center;"|Perihelion distanceat different epochs |- ! Epoch !! Perihelion(AU) |- | 1800 || 2.45 |- | 1859 || 2.11 |- | 1882 || 2.04 |- | 1905 || 1.96 |- | 1965 || 1.49 |- | 2011 || 1.38 |- | 2023 || 1.26 |- | 2036 || 1.36 |- | 2094 || 1.21 |- | 2106 || 1.15 |}

72P/Denning–Fujikawa is a periodic comet discovered on 4 October 1881 by William Frederick Denning. The comet was not seen at another apparition until recovered by Shigehisa Fujikawa in 1978. From 29 December 1978 until 17 June 2014, the comet was lost. On 17 June 2014 the comet was recovered by Hidetaka Sato at apparent magnitude 16 when it was 50 degrees from the Sun. The comet came to perihelion in June 2023, and will next come to perihelion in May 2032.

77P/Longmore is a periodic comet in the Solar System, with a period of 6.8 years. It is the only comet discovered by Australian astronomer, Andrew Jonathan Longmore.

126P/IRAS is a Jupiter-family comet with an orbital period of 13.4 years. It was discovered in images taken by the Infrared Astronomical Satellite (IRAS) on 28 July 1983 by J. Davies. The discovery was confirmed with images taken with the 1.2-m Schmidt telescope at Palomar Observatory.

periodic comet

94P/Russell 4 is a periodic comet in the Solar System.

71P/Clark is a periodic comet in the Solar System with an orbital period of 5.5 years.

300P/Catalina is a periodic, near-Earth comet in the Solar System with an orbital period of 4.4 years. It is the second comet ever listed on the Sentry Risk Table. At in diameter, it is one of the largest objects ever listed on the Sentry Risk Table.

226P/Pigott–LINEAR–Kowalski is a Jupiter family periodic comet with an orbital period of 7.3 years. It was discovered by Edward Pigott on 19 November 1783, but was subsequently lost, until it was recovered on 5 January 2003 by Lincoln Near-Earth Asteroid Research (LINEAR). It will next come to perihelion on 27 December 2023 at about apparent magnitude 15.