Comet Pereyra (formal designations: C/1963 R1, 1963 V, and 1963e) was a bright

comet A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ...

which appeared in 1963. It was a member of the

Kreutz Sungrazers The Kreutz sungrazers ( ) are a family of sungrazing comets, characterized by orbits taking them extremely close to the Sun at perihelion. They are believed to be fragments of one large comet that broke up several centuries ago and are named for G ...

, a group of comets which pass extremely close to the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

Discovery

The comet was first seen on 14 September 1963, by Z.M. Pereyra of Cordoba observatory in

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

observer George Alcock later reported that he had observed a thin pencil-like beam of light low in the sky on 12 September, which may have been the comet's tail. It was bright, at

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

2, and had a short tail about 1 degree long. Over the next few days, the comet faded rapidly, having evidently already passed

perihelion An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elli ...

, although its tail grew to about 10° in length by late September. During its short period of

naked eye Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnifying, light-collecting optical instrument, such as a telescope or microscope, or eye protection. Vision corrected to normal ...

visibility it was widely observed throughout the southern hemisphere.

Orbital studies

As the comet receded from the Sun, orbital studies showed that Pereyra had been a sungrazing comet, passing just 60,000 kilometres from the Sun's surface. Further analysis demonstrated that it was a member of the

, a group of comets all descended from one very large sungrazing comet which fragmented several centuries previously. The Kreutz Sungrazers consist of two major subgroups, which are descended from further breakups of two different fragments of the original comet. Studies have shown that Pereyra is a member of the subgroup which includes the Great Comet of 1843 and the

Great Comet of 1882 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 of the Sun's photosphere at perih ...

, although the separation of Pereyra from the larger fragment probably occurred one

orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as ...

before the two Great Comets separated.

References

Sources

# Marsden B.G. (1967), ''The sungrazing comet group'', Astronomical Journal, v. 72, p. 1170 # Marsden B.G. (1989), ''The sungrazing comet group. II'', Astronomical Journal, v. 98, p. 2306 # Sekanina Z. (1967), ''Definitive orbit of Comet Pereyra (1963 V)'', Bulletin of the Astronomical Institute of Czechoslovakia, v. 18, p.229

External links

cometography.com
{{Comets

Pereyra Pereyra is a surname, a variant of Pereira, and also of Perera. Notable people with the surname include: *Abraham Israel Pereyra (died 1699), very wealthy and important "Portuguese merchant of the Jewish nation," who lived in Amsterdam *Bob Perey ...

1963 in science