 Comet Pereyra photographed by Charles F. Capen from theTable Mountain Observatory on 23 September 1963.[1] | |
| Discovery[2] | |
|---|---|
| Discovered by | Zenon M. Pereyra |
| Discovery site | Cordoba, Argentina |
| Discovery date | 14 September 1963 |
| Designations | |
| 1963 V, 1963e | |
| Orbital characteristics[5] | |
| Epoch | 25 October 1963 (JD 2438327.5) |
| Observation arc | 86 days |
| Number of observations | 12 |
| Orbit type | Kreutz sungrazer |
| Aphelion | 183AU (inbound) 167 AU (outbound)[3] |
| Perihelion | 0.00502 AU (1.08 R☉)[4][a] |
| Semi-major axis | 92 AU (inbound) 84 AU (outbound)[3] |
| Eccentricity | 0.99949 (inbound) 0.99936 (outbound)[3] |
| Orbital period | 875 years (1800)[3] 870 years (1963) 765 years (2200)[3] |
| Inclination | 144.59° |
| 8.052° | |
| Argument of periapsis | 86.231° |
| Mean anomaly | 0.070° |
| Last perihelion | 23 August 1963 |
| TJupiter | –0.015 |
| EarthMOID | 0.556 AU |
| JupiterMOID | 2.985 AU |
| Physical characteristics[6] | |
Mean radius | 13.7 km (8.5 mi) |
| Mass | 3.80×1018 kg |
| Comet total magnitude (M1) | 5.5[7] |
| Comet nuclear magnitude (M2) | 14.3 |
Comet Pereyra (formal designations:C/1963 R1,1963 V, and1963e) was a brightcomet that appeared in 1963. It was a member of theKreutz Sungrazers, a group of comets that pass extremely close to theSun. On 23 August 1963, it passed 56,000 km (35,000 mi) from the Sun's surface.[a]
The comet was first seen on 14 September 1963 by Z.M. Pereyra of theCordoba Observatory inArgentina.British observerGeorge 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. By 20 September, the comet's position was found near the starAlphard in the constellationHydra.[1]
It was bright, with anapparent magnitude of 2, and had a short tail about 1degree long. Over the next few days, the comet faded rapidly, having evidently already passedperihelion, although its tail grew to about 10° in length by late September. During its short period ofnaked eye visibility, it was widely observed throughout theSouthern Hemisphere.
As the comet receded from the Sun, orbital studies showed that Pereyra had been asungrazing comet, passing just 56,000 km (35,000 mi) from the Sun's surface.[a] Further analysis demonstrated that it was a member of theKreutz 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 theGreat Comet of 1843 and theGreat Comet of 1882, although the separation of Pereyra from the larger fragment probably occurred oneorbit before the two Great Comets separated.
A recently discovered comet,C/2026 A1 (MAPS), is likely a member of the same Kreutz subgroup as Pereyra.[8]
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