Discovery [1] | |
---|---|
Discovered by | Kaoru Ikeya |
Discovery site | Maisaka, Japan |
Discovery date | 2 January 1963 |
Designations | |
1963a [2] 1963 I | |
Orbital characteristics [3] | |
Epoch | 26 April 1963 (JD 2438145.5) |
Observation arc | 278 days |
Number of observations | 33 |
Aphelion | 190.5 AU |
Perihelion | 0.632 AU |
Semi-major axis | 95.55 AU |
Eccentricity | 0.99338 |
Orbital period | 934 years |
Inclination | 160.64° |
53.22° | |
Argument of periapsis | 336.30° |
Last perihelion | 21 March 1963 |
TJupiter | –0.874 |
Earth MOID | 0.2364 AU |
Jupiter MOID | 0.5942 AU |
Physical characteristics [4] | |
Comet nuclear magnitude (M2) | 15.0 |
2.8 (1963 apparition) |
C/1963 A1 (Ikeya), also known as Comet 1963I and 1963a, is a long period comet discovered by Kaoru Ikeya on 2 January 1963. The comet last passed perihelion on 21 March 1963, when it reached an apparent magnitude of 2.8. [4]
The comet was discovered by the Japanese amateur astronomer Kaoru Ikeya on 2 January 1963. At that time Kaoru Ikeya was 19 years old and used a self-made 8-inch telescope. The comet was then located three degrees southwest of π Hydrae, [a] had an estimated magnitude of 12 and was diffuse. He confirmed his finding the next day and telegraphed his discovery to the Tokyo Astronomical Observatory, [1] and the new comet was photographed with the Brashear Astrograph. [6]
The comet at discovery was moving rapidly southwards and after 25 January could not be observed from the northern hemisphere. [6] The comet became circumpolar in the southern sky and between February 11 and February 13 was in the constellation of Octans, near the south celestial pole, and then moved northwards. [5] The comet was brightening during February and 15 February was the day of the closest approach of the comet to Earth, at a distance of 0.327 AU (48.9 million km; 30.4 million mi). The comet grew a tail that photographically was estimated to be 8 degrees long on February 18, while it reached third magnitude and was visible with naked eye. The tail originally had a simple straight form but its structure became more complex by the end of the month. [7]
By March 1963 the comet again became visible in the northern hemisphere. By March 10 the apparent magnitude of the comet was estimated to be 4.5. [7] The length of the tail was reported to be as long as nearly 20 degrees on 21 March, the date of the perihelion. [5] After perihelion the comet was in conjunction with the Sun and could not be observed. [7] It reached its minimum elongation of 4° on 12 April. [5]
The comet was recovered in mid-May in the morning sky and was brighter than expected, as the comet faded at a slower rate than it brightened, having a magnitude of 7 to 8. The brighter than expected comet led to some reports that this was a new comet, but photographic observations revealed that there was only one comet in the region, comet Ikeya. In long exposure photographs in mid-June the tail was more than half a degree long. [8] The comet faded rapidly in September and October and was last observed on 12 October. [9]
On March 5 and 6, 1963, spectrograms of the comet could be taken at the Palomar Observatory in California, showing the emission lines of CN, C2 and C3. The ratio of the isotopes 12C/13C could be determined from the intensities. The value was in a range comparable to that on Earth. [10] The spectrum obtained from Lick Observatory showed the presence of diatomic carbon and NH2 and also featured a strong line in λ 6200. [11]
The comet is considered to be the parent body of a number of meteor showers, as it has been modeled to create five streams that intersect with the orbit of Earth. Two of these meteor showers have been identified as π-Hydrids and δ-Corvids. Also the meteor shower of α-Sextantids could also be associated with comet Ikeya. One more meteor shower visible in the data of the Cameras for Allsky Meteor Surveillance, named θ-Leonids is also a good match with the predicted meteor streams. [12]
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.
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.
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A sungrazing comet is a comet that passes extremely close to the Sun at perihelion – sometimes within a few thousand kilometres of the Sun's surface. Although small sungrazers can completely evaporate during such a close approach to the Sun, larger sungrazers can survive many perihelion passages. However, the strong evaporation and tidal forces they experience often lead to their fragmentation.
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.
Comet Arend–Roland was discovered on November 6, 1956, by Belgian astronomers Sylvain Arend and Georges Roland on photographic plates. As the eighth comet found in 1956, it was named Arend–Roland 1956h after its discoverers. Because it was the third comet to pass through perihelion during 1957, it was then renamed 1957 III. Finally, it received the standard IAU designation C/1956 R1 (Arend–Roland), with the "C/" indicating that it was a non-periodic comet and the "R1" showing that it was the first comet reported as discovered in the half-month designated by "R". The last is equivalent to the period September 1–15.
The Kreutz sungrazers are a family of sungrazing comets, characterized by orbits taking them extremely close to the Sun at perihelion. At the far extreme of their orbits, aphelion, Kreutz sungrazers can be a hundred times farther from the Sun than the Earth is, while their distance of closest approach can be less than twice the Sun's radius. They are believed to be fragments of one large comet that broke up several centuries ago and are named for German astronomer Heinrich Kreutz, who first demonstrated that they were related. These sungrazers make their way from the distant outer Solar System to the inner Solar System, to their perihelion point near the Sun, and then leave the inner Solar System in their return trip to their aphelion.
Comet Bennett, formally known as C/1969 Y1, was one of the two bright comets observed in the 1970s, along with Comet West and is considered a great comet. The name is also borne by an altogether different comet, C/1974 V2. Discovered by John Caister Bennett on December 28, 1969, while still almost two AUs from the Sun, it reached perihelion on March 20, passing closest to Earth on 26 March 1970, as it receded, peaking at magnitude 0. It was last observed on 27 February 1971.
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 C/1861 G1 (Thatcher) is a long-period comet with roughly a 422-year orbit that is expected to return around 2283. It was discovered by A. E. Thatcher. It is responsible for the April Lyrid meteor shower. Carl Wilhelm Baeker also independently found this comet. The comet passed about 0.335 AU from the Earth on 5 May 1861 and last came to perihelion on 3 June 1861.
332P/Ikeya–Murakami is a short-period comet with period of approximately 5.4 years first identified independently by the two Japanese amateur astronomers Kaoru Ikeya and Shigeki Murakami on November 3, 2010. Ikeya identified the comet using a 25-centimeter (10-inch) reflector at 39×, while Murakami used a 46 cm (18-inch) reflector at 78×. Photographic confirmation of the comet was obtained by Ernesto Guido and Giovanni Sostero using a Global-Rent-a-Scope (GRAS) telescope in New Mexico. Both Ikeya and Murakami discovered the comet using manual observation through optical telescopes. Such visual discoveries have become rare in recent years.
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C/1964 N1 (Ikeya), also known as Comet 1964f, is a long period comet discovered by Kaoru Ikeya on 3 July 1964. The comet last passed perihelion on 1 August 1964, when it reached an apparent magnitude of 2.7.
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