Discovery | |
---|---|
Discovered by | T. Lovejoy K. Černis B. Zhou S. F. Hönig |
Discovery date | September 4, 1999 |
Designations | |
P/1999 R1, P/2003 R5, P/2007 R5, P/2011 R4 | |
Orbital characteristics | |
Epoch | 2019-08-25 (JD 2458720.5) [1] |
Observation arc | 15.9 years |
Number of observations | 318 |
Aphelion | 4.967 AU |
Perihelion | 0.0507 AU (16% of Mercury's perihelion) |
Semi-major axis | 2.509 AU |
Eccentricity | 0.9798 |
Orbital period | 3.97 yr |
Max. orbital speed | 187 km/s (2023) [2] |
Min. orbital speed | 1.9 km/s (2017-Sep-01) |
Inclination | 11.46° |
Last perihelion | August 31, 2019 [1] September 4, 2015 [1] September 7, 2011 [1] September 11, 2007 [1] |
Next perihelion | August 21, 2023 [2] |
TJupiter | 2.347 |
Earth MOID | 0.092 AU (13,800,000 km) |
Physical characteristics | |
Dimensions | ~100-200 m |
Comet total magnitude (M1) | 19.00 ± 0.09 |
Perihelion distance at different epochs [3] | |||||||
Perihelion date | Perihelion (AU) | ||||||
---|---|---|---|---|---|---|---|
1955-04-18 | 0.0651 | ||||||
1983-08-08 | 0.0597 | ||||||
1999-09-05 | 0.0563 | ||||||
2015-09-04 | 0.0535 | ||||||
2019-08-31 | 0.0506 | ||||||
2023-08-21 | 0.0501 | ||||||
2027-08-11 | 0.0505 | ||||||
2031-08-01 | 0.0479 | ||||||
2047-05-23 | 0.0451 |
Comet 322P/SOHO, also designated P/1999 R1, P/2003 R5, P/2007 R5, and P/2011 R4, is the first periodic comet to be discovered using the automated telescopes of the SOHO (SOlar and Heliospheric Observatory) spacecraft, and second to be given a numbered designation, after 321P/SOHO. JPL Horizons next predicts 322P to come to perihelion (closest approach to the Sun) on 21 August 2023 at around apparent magnitude 6 and only 3 degrees from the Sun. [2] At perihelion it is six times closer to the Sun than the planet Mercury is at perihelion.
The periodicity of this comet was predicted by Sebastian Hönig, a German graduate student and prolific asteroid discoverer, in 2006. [4] The announcement of the new periodic comet was made after the predicted return was confirmed by SOHO and observer Bo Zhou on 10 September 2007. [5] Out of approximately 1,350 SOHO-observed sungrazer comets, this is the first to be verified as a short-period comet; most sungrazers are long-period comets on near-parabolic orbits that do not repeat for thousands of years, if at all.
As it passed to within 7.9 million kilometres of the Sun, around 0.05 AU, it brightened by a factor of around a million. This is common behavior for a comet. [6] It was expected to return in September 2011, [6] and was recovered by B. Zhou on September 6, 2011. Discovery credit goes to Terry Lovejoy (Australia, 1999), Kazimieras Černis (Lithuania, 2003), and Bo Zhou (China, 2007). It was observed again in September 2019. [7]
P/2007 R5 is probably an extinct comet. Extinct comets are those that have expelled most of their volatile ice and have little left to form a tail or coma. They are theorized to be common objects amongst the celestial bodies orbiting close to the Sun. P/2007 R5 (SOHO) is probably only 100–200 meters in diameter. [6] It has a 2.8 hour light curve period suggesting its rotation. It is uncertain whether to classify it as a dead comet or asteroid. [8]
It has been suggest than 322P/SOHO is associated with a comet observed in 254 CE and is mentioned in east-asian sources to have an extremely long tail. If the association is correct, it is possible that the comet split in 254 CE, resulting in intense cometary activity, but activity decreased afterwards as the comet lost most of its volatiles, and no longer displays a tail or a prominent coma. Current activity is fueled by sodium sublimation. [9]
On April 11, 1947 it passed about 7.1 ± 0.22 million km (4.4 ± 0.14 million mi) from Earth. [10] [11]
The second periodic comet discovered by SOHO is P/2003 T12 (SOHO). [12]
Comet Encke, or Encke's Comet, is a periodic comet that completes an orbit of the Sun once every 3.3 years. Encke was first recorded by Pierre Méchain on 17 January 1786, but it was not recognized as a periodic comet until 1819 when its orbit was computed by Johann Franz Encke. Like Halley's Comet, it is unusual in its being named after the calculator of its orbit rather than its discoverer. Like most comets, it has a very low albedo, reflecting only 4.6% of the light its nucleus receives, although comets generate a large coma and tail that can make them much more visible during their perihelion. The diameter of the nucleus of Encke's Comet is 4.8 km.
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.
The Great Comet of 1882 formally designated C/1882 R1, 1882 II, and 1882b, was a comet which became very bright in September 1882. It was a member of the Kreutz Sungrazers, a family of comets which pass within 1 R☉ of the Sun's photosphere at perihelion. The comet was bright enough to be visible next to the Sun in the daytime sky at its perihelion. The comet made its closest approach to Earth on 16 September 1882 at 0.99 AU and then came to perihelion the next day on 17 September.
Comet Pereyra was a bright comet that appeared in 1963. It was a member of the Kreutz Sungrazers, a group of comets that pass extremely close to the Sun.
Comet Ikeya–Zhang is a comet discovered independently by two astronomers from Japan and China in 2002. It has by far the longest orbital period of the numbered periodic comets. It was last observed in October 2002 when it was about 3.3 AU (490 million km) from the Sun.
73P/Schwassmann–Wachmann, also known as Schwassmann–Wachmann 3 or SW3 for short, is a periodic comet that has a 5.4 year orbital period and that has been actively disintegrating since 1995. When it came to perihelion in March 2017, fragment 73P-BT was separating from the main fragment 73P-C. Fragments 73P-BU and 73P-BV were detected in July 2022. The main comet came to perihelion on 25 August 2022, when the comet was 0.97 AU from the Sun and 1 AU from Earth. It will be less than 80 degrees from the Sun from 25 May 2022 until August 2023. On 3 April 2025 it will make a modest approach of 0.3 AU to Jupiter. 73P will next come to perihelion on 23 December 2027 when it will be 0.92 AU from the Sun and on the far side of the Sun 1.9 AU from Earth.
157P/Tritton is a periodic comet with a 6-year orbital period. Fragment B was first observed on 21 August 2022.
11P/Tempel–Swift–LINEAR is a periodic Jupiter-family comet in the Solar System.
13P/Olbers is a periodic comet with an orbital period of 69 years. It fits the classical definition of a Halley-type comet with a period between 20 and 200 years. The comet last passed perihelion 30 June 2024 and it was previously seen in 1956. The next perihelion is in 2094.
20D/Westphal was a periodic comet with an orbital period of 61 years. It fits the classical definition of a Halley-type comet. The comet appeared to disintergrate during the 1913 apparition and hasn't been observed since then.
Comet 177P/Barnard, also known as Barnard 2, is a periodic comet with an orbital period of 122 years. It fits the classical definition of a Halley-type comet with. It orbits near the ecliptic plane and has aphelion near the Kuiper cliff at 48 AU (7.2 billion km).
118401 LINEAR (provisional designation 1999 RE70, comet designation 176P/LINEAR) is an active asteroid and main-belt comet that was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) 1-metre telescopes in Socorro, New Mexico on September 7, 1999. (118401) LINEAR was discovered to be cometary on November 26, 2005, by Henry H. Hsieh and David C. Jewitt as part of the Hawaii Trails project using the Gemini North 8-m telescope on Mauna Kea and was confirmed by the University of Hawaii's 2.2-m (88-in) telescope on December 24–27, 2005, and Gemini on December 29, 2005. Observations using the Spitzer Space Telescope have resulted in an estimate of 4.0±0.4 km for the diameter of (118401) LINEAR.
Comet 96P/Machholz or 96P/Machholz 1 is a short-period sungrazing comet discovered on May 12, 1986, by amateur astronomer Donald Machholz on Loma Prieta peak, in central California using 130 millimetres (5.1 in) binoculars. On June 6, 1986, 96P/Machholz passed 0.404 AU from the Earth. 96P/Machholz last came to perihelion on January 31, 2023. The comet has an estimated diameter of around 6.4 km (4.0 mi).
94P/Russell 4 is a periodic comet in the Solar System. It fits the definition of an Encke-type comet with. It was discovered by Ken Rusell on photographic plates taken by M. Hawkins on March 7, 1984. In the discovery images, Russell estimated that the comet had an apparent magnitude of 13 and a noticeable tail of 5 arc minutes. In the year of discovery, the comet had come to perihelion in January 1984.
Comet Lovejoy, formally designated C/2011 W3 (Lovejoy), is a long-period comet and Kreutz sungrazer. It was discovered in November 2011 by Australian amateur astronomer Terry Lovejoy. The comet's perihelion took it through the Sun's corona on 16 December 2011, after which it emerged intact, though greatly impacted by the event.
62P/Tsuchinshan, also known as Tsuchinshan 1, is a periodic comet first discovered January 1, 1965 at the Purple Mountain Observatory in Nanking. It last came to perihelion on 25 December 2023 at around apparent magnitude 8, and was then 0.53 AU (79 million km) from Earth and 110 degrees from the Sun.
51P/Harrington is a periodic comet in the Solar System.
273P/Pons–Gambart, also called Comet Pons-Gambart, is a periodic comet in a retrograde orbit first discovered on June 21, 1827 by Jean-Louis Pons and Jean-Félix Adolphe Gambart. It has a 186 year orbit and it fits the classical definition of a Halley-type comet. Its last perihelion was in December 2012 and will next come to perihelion around August 2191.
156P/Russell–LINEAR is a Jupiter family periodic comet with an orbital period of 6.4 years. It was discovered by Kenneth S. Russell in September 1986.
323P/SOHO is a periodic comet with an orbital period of 4.15 years discovered in images obtained by the Solar and Heliospheric Observatory (SOHO). It is considered to be a sungrazing comet due to its perihelion being very close to the Sun. 323P/SOHO has the smallest perihelion of all numbered comets.