Comet Ikeya–Seki, formally designated C/1965 S1, 1965 VIII, and 1965f, was a long-period comet discovered independently by Kaoru Ikeya and Tsutomu Seki. First observed as a faint telescopic object on 18 September 1965, the first calculations of its orbit suggested that on October 21, it would pass just 450,000 km (280,000 mi) above the Sun's surface, and would probably become extremely bright.
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. However it has been confirmed 12P/Pons–Brooks was observed before the 19th century.
The Great Comet of 1882, formally designated as 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 Great Comet of 1861, formally designated C/1861 J1 and 1861 II, is a long-period comet that was visible to the naked eye for approximately 3 months. It was categorized as a great comet—one of the eight greatest comets of the 19th century.
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.
Comet Holmes is a periodic comet in the Solar System, discovered by the British amateur astronomer Edwin Holmes on November 6, 1892. Although normally a very faint object, Holmes became notable during its October 2007 return when it temporarily brightened by a factor of a million, in what was the largest known outburst by a comet, and became visible to the naked eye. It also briefly became the largest object in the Solar System, as its coma expanded to a diameter greater than that of the Sun. Between 1857–2106 perihelion remains between 2.05–2.36 AU.
The Comet of 1729, also known as C/1729 P1 or Comet Sarabat, was an assumed parabolic comet with an absolute magnitude of −3, possibly the brightest ever observed for a comet; it is therefore considered to be potentially the largest comet ever seen. With an assumed eccentricity of 1, it is unknown if this comet will return in a hundred thousand years or be ejected from the Solar System.
Comet McNaught, also known as the Great Comet of 2007 and given the designation C/2006 P1, is a non-periodic comet discovered on 7 August 2006 by British-Australian astronomer Robert H. McNaught using the Uppsala Southern Schmidt Telescope. It was the brightest comet in over 40 years, and was easily visible to the naked eye for observers in the Southern Hemisphere in January and February 2007.
Comet McNaught–Russell, formally designated as C/1993 Y1, is a long-period comet that reached a maximum magnitude of 6.5 in early 1994. It was discovered by Robert H. McNaught and Kenneth S. Russell using the U.K. Schmidt Telescope in Australia. McNaught and Russell worked at Siding Spring Observatory and together discovered five comets between 1991 and 1995.
The Great Comet of 1744, whose official designation is C/1743 X1, and which is also known as Comet de Chéseaux or Comet Klinkenberg-Chéseaux, was a spectacular comet that was observed during 1743 and 1744. It was discovered independently in late November 1743 by Jan de Munck, in the second week of December by Dirk Klinkenberg, and, four days later, by Jean-Philippe de Chéseaux. It became visible with the naked eye for several months in 1744 and displayed dramatic and unusual effects in the sky. Its absolute magnitude – or intrinsic brightness – of 0.5 was the sixth highest in recorded history. Its apparent magnitude may have reached as high as −7, leading it to be classified as a Great Comet. This comet is noted especially for developing a 'fan' of six tails after reaching its perihelion.
Ryves's Comet, also known as C/1931 P1, 1931 IV or 1931c, was discovered by Percy Mayow Ryves, an English amateur astronomer, on 10 August 1931. The comet passed perihelion on 25 August 1931 at a distance of 0.075 AU from the Sun.
C/1989 X1 (Austin) was a comet discovered by New Zealand amateur Rodney R. D. Austin on December 6, 1989. The comet at discovery was predicted to become easily visible by naked eye in spring 1990, however it failed to become that bright.
C/1881 K1, also called the Great Comet of 1881, Comet Tebbutt, 1881 III, and 1881b, is a non-periodic comet discovered by Australian amateur astronomer John Tebbutt on 22 May 1881 at Windsor, New South Wales. It is called a great comet because of its brightness at its last apparition.
The Great Southern Comet of 1865, also known as C/1865 B1 by its modern nomenclature, was a non-periodic comet, which in 1865 was so bright that it was visible to unaided-eye observations in the Southern Hemisphere. The comet could not be seen from the Northern Hemisphere.
C/2019 Y4 (ATLAS) was a comet with a near-parabolic orbit discovered by the ATLAS survey on December 28, 2019. Early predictions based on the brightening rate suggested that the comet could become as bright as magnitude 0 matching the brightness of Vega. It received widespread media coverage due to its dramatic increase in brightness and orbit similar to the Great Comet of 1844, but on March 22, 2020, the comet started disintegrating. Such fragmentation events are very common for Kreutz Sungrazers. The comet continues to fade and did not reach naked eye visibility. By mid-May, comet ATLAS appeared very diffuse even in a telescope. C/2019 Y4 (ATLAS) has not been seen since May 21, 2020.
C/2020 F3 (NEOWISE) or Comet NEOWISE is a long period comet with a near-parabolic orbit discovered on March 27, 2020, by astronomers during the NEOWISE mission of the Wide-field Infrared Survey Explorer (WISE) space telescope. At that time, it was an 18th-magnitude object, located 2 AU away from the Sun and 1.7 AU away from Earth.
The Southern Comet of 1947 was a bright comet that became visible in the southern hemisphere in December 1947. At that point, it was the brightest comet seen in two decades and is one of the brightest comets seen since 1935, with an estimated maximum apparent magnitude of -3.
C/2004 F4 (Bradfield) is a non-periodic comet discovered by amateur astronomer William A. Bradfield on 23 March 2004. The comet brightened to an apparent magnitude of about 3.3.
C/2024 G3 (ATLAS) is a long-period, sungrazing comet, which will reach perihelion on 13 January 2025, at a distance of 0.09 AU from the Sun. It could become the brightest comet of 2025, possibly exceeding apparent magnitude of −3.5. The comet is visible in the southern hemisphere before and after perihelion. It can only be observed in the daytime sky around perihelion in the northern hemisphere.
Comet Tago–Sato–Kosaka, formally designated as C/1969 T1, is a non-periodic comet that became visible in the naked eye between late 1969 and early 1970. It was the first comet ever observed by an artificial satellite.
