Ikeya-Zhang on April 1, 2002 |
|
| Discovery | |
|---|---|
| Discovered by: | Kaoru Ikeya, Zhang Daqing |
| Discovery date: | February 1, 2002 |
| Alternate designations: | C/2002 C1 |
| Orbital characteristics A | |
| Epoch: | October 13, 2002 |
| Aphelion: | 101.9200 AU |
| Perihelion: | 0.507141 AU |
| Semi-major axis: | 51.2136 AU |
| Eccentricity: | 0.990098 |
| Orbital period: | 366.5101 yr[1] |
| Inclination: | 28.1199° |
| Last perihelion: | March 18, 2002[1] January 29, 1661[2] |
| Next perihelion: | September 1, 2362[2] |
Comet Ikeya-Zhang (Chinese, Japanese: 池谷-張彗星, officially designated 153P/Ikeya–Zhang) is a comet discovered independently by two astronomers from Japan and China in 2002.
On February 1, 2002, Chinese astronomer Zhang Daqing from Kaifeng discovered a new comet in the constellation Cetus, and reported it to the IAU. He found that Japanese astronomer Kaoru Ikeya had discovered it earlier than he had, as the time of sunset is earlier than China. According to tradition, since they discovered the new comet independently, the comet was named after both of them. The comet was initially designated as C/2002 C1 (Ikeya-Zhang).
The comet passed perihelion on March 18, 2002, and with apparent magnitude 3.5, it became the brightest comet since 1997. The orbital period was calculated as 366.51 years. A bright comet had been recorded by Chinese astronomers in 1661, 341 years earlier, and confirmed comet Ikeya-Zhang was the return of the 1661 comet recorded by the astronomers. The permanent designation "153P" was given to the comet, and it is the periodic comet with the longest known orbital period.
| Periodic comets (by number) | ||
|---|---|---|
| Previous 152P/Helin-Lawrence |
153P/Ikeya–Zhang | Next 154P/Brewington |