| Discovery | |
|---|---|
| Discovered by: | Terry Lovejoy, Kazimieras Cernis, Bo Zhou, and Sebastian Hönig |
| Discovery date: | September 4, 1999 |
| Alternate designations: | P/1999 R1, P/2003 R5 |
| Orbital characteristics A | |
| Aphelion: | 4.9903 AU |
| Perihelion: | 0.0570 AU |
| Semi-major axis: | 2.5237 AU |
| Eccentricity: | 0.9774 |
| Orbital period: | 4.01 yr |
| Inclination: | 13.676° |
| Last perihelion: | September 11, 2007 |
| Next perihelion: | September 7, 2011 |
Comet P/2007 R5 (SOHO), also designated P/1999 R1 and P/2003 R5, is the first periodic comet to be discovered using the automated telescopes of the SOHO (SOlar and Heliospheric Observatory) spacecraft.
The periodicity of P/2007 R5 was predicted by Sebastian F. Hönig, a German graduate student and prolific asteroid discoverer, in 2006.[1] 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.[2] 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 5% of the distance from the Earth to the Sun, it brightened by a factor of around a million. This is common behavior for a comet.[3]
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.[3]
It was expected to return in September 2011,[3] and was recovered by B. Zhou on September 6, 2011.[4]
Discovery credit goes to Terry Lovejoy (Australia, 1999), Kazimieras Černis (Lithuania, 2003), and Bo Zhou (China, 2007).