45P/Honda–Mrkos–Pajdušáková
Periodic comet with 5 year orbit
From Wikipedia, the free encyclopedia
45P/Honda–Mrkos–Pajdušáková is a short-period comet discovered by Minoru Honda December 3, 1948.[7] It is named after Minoru Honda, Antonín Mrkos, and Ľudmila Pajdušáková. The object revolves around the Sun on an elliptical orbit with a period of 5.25 years.[3] The nucleus is 1.3 kilometers in diameter.[5] On August 19 and 20, 2011, it became the fifteenth comet detected by ground radar telescope.[8]
Comet Honda–Mrkos–Pajdušáková on February 10, 2017 | |
| Discovery | |
|---|---|
| Discovered by | Minoru Honda |
| Discovery date | December 3, 1948 |
| Designations | |
| Pronunciation | /ˈhɒndə ˈmɜːrkɒs ˌpaɪduːʃəˈkoʊvə/ |
| Orbital characteristics | |
| Epoch | 2025-11-21 (JD 2461000.5) |
| Aphelion | 5.56 AU |
| Perihelion | 0.558 AU |
| Semi-major axis | 3.06 AU |
| Eccentricity | 0.817 |
| Orbital period | 5.34 yr |
| Inclination | 4.32° |
| Last perihelion | April 26, 2022[1] December 31, 2016[2] September 28, 2011[3] |
| Next perihelion | 2027-Aug-30[4] |
| Earth MOID | 0.06 AU (9.0 million km)[3] |
| Jupiter MOID | 0.105 AU (15.7 million km)[3] |
| Physical characteristics[5][6] | |
| Dimensions | 1.3 km |
| 7.6±0.5 hours | |
By May 2027, the comet should be around apparent magnitude 14. The comet reaches perihelion on 30 August 2027,[4] when it should brighten to magnitude 5-8.
During the 1995 perihelion passage, the comet was visible to Solar and Heliospheric Observatory (SOHO) on January 16, 1996, when the comet was around apparent magnitude 7 and 4.3° from the Sun.[7]
It is green because it emits diatomic carbon which glows green in the near vacuum of space.[9]
2011 passage
During the 2011 perihelion passage, the comet was recovered on 5 June at magnitude 21.[10] On 8 July, the comet had a magnitude of approximately 18,[11] and, as of 22 July, nuclear condensation was noticed around magnitude 16.[12] It was expected to reach a peak magnitude of around 7.3 in late September near perihelion.[13]
On August 15, 2011, the comet made a close approach of only 0.0600 AU (8,980,000 km; 5,580,000 mi) from the Earth[14][15][16] and it was studied by the Goldstone Deep Space Network.[17] Radar observations on August 19 and 20 detected echoes from the nucleus and coma.[8]
2017 passage
45P/Honda–Mrkos–Pajdušáková came to perihelion on December 31, 2016.[3] By February 4, 2017, it was around magnitude 7 and the coma was about 100,000 km across.[18] The comet required binoculars to be seen because of the low surface brightness.[19] The comet passed 0.08318 AU (12,444,000 km; 7,732,000 mi) from Earth on February 11, 2017, which was the same day as a lunar eclipse.[15][20]
 |
| This shows the path of the comet during January through March 2017, with daily motion drawn as spheres, scaled for relative distance from earth. |
The next notable close approach will be in October 2032[15] when the comet might brighten to magnitude 7.
August Delta Capricornids
On 16 August 2022 the global CAMS and Sonotaco network detected a modest outburst of meteors with an orbit that resembled comet 45P.[21] The shower received the temporary designation of M2022-Q1, and was later permanently named the August Delta Capricornids.[22] The meteors had an entry speed of 24.4 km/s and originated from the border of Aquarius and Capricornus with R.A. 21:40 and a declination of –11.9°.[21] This was the first time an encounter with a dust trail of 45P has been confirmed and it came from the 1980 meteoroid stream of 45P.[22] In all, 137 meteors were triangulated by the global CAMS networks.
