Comet Pereyra

Comet Pereyra
	Comet Pereyra on September 23, 1963
Discovery
Discovered by	Zenon M. Pereyra
Discovery date	14 September 1963
Designations
Alternative designations	C/1963 R1, 1963 V, 1963e
Orbital characteristics
Epoch	1963-Oct-25.0
Observation arc	86 days
Number of; observations	12
Aphelion	182 AU
Perihelion	0.005 AU
Semi-major axis	91 AU
Eccentricity	0.999945
Orbital period	875 years (1800); 870 years (1963); 765 years (2200)
Inclination	144.60°
Longitude of; ascending node	8.05°
Argument of; periapsis	86.23°
Last perihelion	23 August 1963
Earth MOID	0.56 AU
Comet nuclear; magnitude (M2)	14.3

Comet Pereyra (formal designations: C/1963 R1, 1963 V, and 1963e) 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.

Discovery

The comet was first seen on 14 September 1963 by Z.M. Pereyra of the Cordoba Observatory in Argentina. British 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, with an apparent magnitude of 2, and had a short tail about 1 degree long. Over the next few days, the comet faded rapidly, having evidently already passed perihelion, although its tail grew to about 10° in length by late September. During its short period of naked eye 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 Kreutz Sungrazers, a group of comets all descended from one very large sungrazing comet that fragmented several centuries ago.

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 that includes the Great Comet of 1843 and the Great Comet of 1882, although the separation of Pereyra from the larger fragment probably occurred one orbit before the two Great Comets separated.

References

^ ^a ^b Horizons output. "Barycentric Osculating Orbital Elements for Comet Pereyra (C/1963 R1)". Retrieved 2023-09-02. (Solution using the Solar System's barycenter (Sun+Jupiter). Select Ephemeris Type and Center:@0)
Epoch 1800: PR= 3.197E+05 / 365.25 = 875 years
Epoch 2200: PR= 2.794E+05 / 365.25 = 765 years
^ "Small-Body Database Lookup: C/1963 R1 (Pereyra)". ssd.jpl.nasa.gov.

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