322P/SOHO
| Discovery | |
|---|---|
| Discovered by | Terry Lovejoy, Kazimieras Cernis, Bo Zhou, and Sebastian Hönig |
| Discovery date | September 4, 1999 |
| Designations | |
| P/1999 R1, P/2003 R5, P/2007 R5, P/2011 R4 | |
| Orbital characteristics | |
| Epoch | 2013-Jan-01 (JD 2456293.5) |
| Number of observations | 299 |
| Aphelion | 4.978257 AU |
| Perihelion | 0.05338 AU |
| Semi-major axis | 2.5158179 AU |
| Eccentricity | 0.978783 |
| Orbital period | 3.99 yr |
| Max. orbital speed | 186 km/s (2019) |
| Min. orbital speed | 1.9 km/s (2017-Sep-01) |
| Inclination | 12.630° |
| Last perihelion | 2015-Sep-04[1] September 7, 2011[1] September 11, 2007[1] |
| Next perihelion | 2019-08-31[1] |
| TJupiter | 2.346 |
| Earth MOID | 0.092 AU (13,800,000 km) |
| Physical characteristics | |
| Dimensions | ~100-200 m |
| Comet total magnitude (M1) | 19.00 ± 0.09 |
Comet 322P/SOHO, also designated P/1999 R1, P/2003 R5, P/2007 R5, and P/2011 R4, is the first periodic comet to be discovered using the automated telescopes of the SOHO (SOlar and Heliospheric Observatory) spacecraft, and second to be given a numbered designation, after 321P/SOHO.
The periodicity of P/2007 R5 was predicted by Sebastian F. Hönig, a German graduate student and prolific asteroid discoverer, in 2006.[2] The announcement of the new periodic comet was made after the predicted return was confirmed by SOHO and observer B. Zhou on 10 September 2007.[3] Out of approximately 1,350 SOHO-observed sungrazer comets, this is the first to be verified as a short-period comet; most sungrazers are long-period comets on near-parabolic orbits that do not repeat for thousands of years, if at all.
As it passed to within 7.9 million kilometres of the Sun, around .05 AU, it brightened by a factor of around a million. This is common behavior for a comet.[4]
P/2007 R5 is probably an extinct comet. Extinct comets are those that have expelled most of their volatile ice and have little left to form a tail or coma. They are theorized to be common objects amongst the celestial bodies orbiting close to the Sun. P/2007 R5 (SOHO) is probably only 100–200 meters in diameter.[4]
It was expected to return in September 2011,[4] and was recovered by B. Zhou on September 6, 2011.[5]
Discovery credit goes to Terry Lovejoy (Australia, 1999), Kazimieras Černis (Lithuania, 2003), and Bo Zhou (China, 2007).
The second periodic comet discovered by SOHO is P/2003 T12 (SOHO).[6]
References
- ^ a b c d "322P/SOHO Orbit". Minor Planet Center. Retrieved 2017-04-10.
- ^ Jaggard, Victoria (2007-09-25). "Photo in the News: Sun Probe Spies New Periodic Comet". National Geographic News. National Geographic Society. Retrieved 2007-09-25.
- ^ Marsden, Brian (18 September 2007), "MPEC 2007-S16 : COMET P/1999 R1 = 2003 R5 = 2007 R5 (SOHO)", Minor Planet Electronic Circular (2007-S16)
- ^ a b c "SOHO's new catch: its first officially periodic comet". European Space Agency. 25 September 2007. Retrieved 2007-11-19.
- ^ Rainer Kracht (2011-09-07). "Recent comet discoveries 2123-2137". Yahoo Groups: SOHO Hunter. Retrieved 2011-09-11.
- ^ Karl Battams (Jan 30, 2012). "The tale of a very shy comet..." Sungrazing Comets @ Navy.mil. Retrieved 2012-01-30.
External links
- Orbital simulation from JPL (Java) / Ephemeris
- SOHO's first officially periodic comet
- SOHO Comets (view real-time images)
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