P/2007 R5

Infobox Comet
name=P/2007 R5 (SOHO)
discoverer= Terry Lovejoy, Kazimieras Cernis, Bo Zhou, and Sebastian Hönig
discovery_date=September 4 1999
designations=P/1999 R1, P/2003 R5
semimajor=2.5237 AU
perihelion=0.0570 AU
aphelion=4.9903 AU
eccentricity=0.9774
period=4.01 a
inclination= 13.676°
last_p=September 11, 2007
next_p=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 [cite news
last = Jaggard
first = Victoria
title = Photo in the News: Sun Probe Spies New Periodic Comet
work = National Geographic News
publisher = National Geographic Society
date = 2007-09-25
url = http://news.nationalgeographic.com/news/2007/09/070925-new-comet.html
accessdate = 2007-09-25 ] . 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 [Citation
last = Marsden
first = Brian
title = MPEC 2007-S16 : COMET P/1999 R1 = 2003 R5 = 2007 R5 (SOHO)
journal = Minor Planet Electronic Circular
issue = 2007-S16
date = 18 September
year = 2007
url = http://www.cfa.harvard.edu/mpec/K07/K07S16.html ] . 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 brighten by a factor of around a million. This is common behavior for a comet.cite web|date=25 September 2007|title=SOHO's new catch: its first officially periodic comet|publisher=European Space Agency |url=http://www.esa.int/esaCP/SEMAU2C1S6F_index_0.html|accessdate=2007-11-19]

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.

It is due to return in September 2011.

Discovery credit goes to Terry Lovejoy (Australia, 1999), Kazimieras Černis (Lithuania, 2003), and Bo Zhou (China, 2007).

References

External links

* [http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=P/2007+R5;orb=1 Orbital simulation] from JPL (Java) / [http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=P/2007+R5 Ephemeris]
* [http://sohowww.nascom.nasa.gov/hotshots/2007_09_24/ SOHO's first officially periodic comet]
* [http://ares.nrl.navy.mil/sungrazer/ SOHO Comets] (view real-time images)

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