C / 1983 H1 (IRAS-Araki-Alcock)
| C / 1983 H1 (IRAS-Araki-Alcock) [i] | |
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False color image of the comet captured in the infrared by the Infrared Astronomical Satellite
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| Properties of the orbit ( animation ) | |
| Orbit type | long-period |
| Numerical eccentricity | 0.9898 |
| Perihelion | 0.991 AU |
| Aphelion | 194.2 AU |
| Major semi-axis | 97.6 AU |
| Sidereal period | ~ 964 a |
| Inclination of the orbit plane | 73.3 ° |
| Perihelion | May 21, 1983 |
| Orbital velocity in the perihelion | 42.2 km / s |
| Physical properties of the core | |
| Medium diameter | 9.2 km |
| Albedo | 0.02 |
| history | |
| Explorer | Infrared Astronomical Satellite , Genichi Araki , George Alcock |
| Date of discovery | April 25, 1983 |
| Older name | 1983 VII, 1983d |
| Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles . | |
C / 1983 H1 (IRAS-Araki-Alcock) is a comet that came closer to Earth in 1983 (about 5,000,000 km) than any other comet in the last 200 years; only Lexell's comet in 1770 and 55P / Tempel-Tuttle in 1366 came even closer to Earth.
The comet was named after its discoverers - the Infrared Astronomical Satellite and two amateur astronomers: the highly respected George Alcock from the UK and Genichi Araki from Japan (both men were teachers, Alcock was retired). Alcock had made his discovery simply by looking through the window of his house with binoculars.
During the closest approach of the comet it appeared as a circular cloud about the size of the full moon, with no discernible tail and with an apparent brightness between 3 and 4 mag visible to the naked eye in dark skies. He was moving across the sky at a high speed of around 30 degrees per day.
The comet is long-period with an orbital period of around 964 years. IRAS-Araki-Alcock is the parent comet that causes the small meteor shower Eta-Lyriden . The radiant of this meteor shower lies between the constellations Lyra and Cygnus , it delivers 1 to 2 meteors per hour in mid-May each year with a maximum between May 9 and 11.
Individual evidence
- ↑ C / 1983 H1 (IRAS-Araki-Alcock). Retrieved June 27, 2017 .
- ^ Obituary of George Alcock. BBC , accessed June 27, 2017 .
- ↑ ' Outbreak of Comet Fever ', TIME Magazine , 23-05-83. "I've discovered a wonderful star," commented Araki, "Now I've got to discover a wonderful wife."
- ↑ ' Eta Lyrids ( Memento from May 5, 2012 in the Internet Archive )', Meteor Showers Online, accessed 21-11-08