354P/LINEAR

Discovery

P/2010 A2 was discovered on 6 January 2010 by Lincoln Near-Earth Asteroid Research (LINEAR) using a 1 m reflecting telescope with a CCD camera. It was LINEAR's 193rd comet discovery. It has been observed over a 112-day arc of the 3.5 year orbit. It appears to have come to perihelion (closest approach to the Sun) around the start of December 2009, about a month before it was discovered.

Orbit

With an aphelion (furthest distance from the Sun) of only 2.6 AU, P/2010 A2 spends all of its time inside of the frost line at 2.7 AU.{{Cite web |access-date = 2010-01-20 |archive-url = https://web.archive.org/web/20100214120720/http://www.deepfly.org/TheNeighborhood/Glossary.html |archive-date = 2010-02-14 |url-status = dead |access-date=2010-02-03 |author-link=David C. Jewitt |access-date=2010-01-20}} Early modeling indicated that the asteroid became active in late March 2009, reached maximum activity in early June 2009, and eased activity in early December 2009.{{Cite web |access-date=2010-07-27

The orbit of P/2010 A2 is consistent with membership in the Flora asteroid family, produced by collisional shattering more than 100 million years ago. The Flora family of asteroids may be the source of the Chicxulub (Cretaceous–Paleogene) impactor, the likely culprit in the extinction of the dinosaurs. One asteroid of the Flora family, , was initially suspected to have collided with P/2010 A2 due to their very similar orbits, but was later deemed a coincidence.{{cite web

Cause of activity

Observations with the Hubble Space Telescope and the narrow angle camera on board the Rosetta spacecraft indicate that the dust trail seen was probably created by the impact of a small meter size object on the larger asteroid in February or March 2009, although it cannot be ruled out that the asteroid's rotation increased from solar radiation resulting in a loss of mass that formed a comet-like tail.{{cite web |access-date=2010-10-15}}

P/2010 A2 is likely about 150 m in diameter. Even when it was discovered it was suspected of being less than 500 meters in diameter.{{Cite web |author-link=Jonathan Shanklin |access-date=2010-01-21}}

References

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References

1. [http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=354P JPL Horizons] Observer Location: @sun (Perihelion occurs when deldot changes from negative to positive.)
2. This absolute asteroidal [[Photometric system. V]] magnitude has been calculated using comet/asteroid magnitude analysis software [http://aerith.net/project/comet.html "Comet for Windows"] from value of [[Photometric system. 23.0. 0.5 taken from IAU Circular No. 9109. The mean V-R color index for asteroids is {{Val. +0.4. 0.1.
3. [http://www.astronomytoday.com/blog/hst-sees-evidence-colliding-asteroids HST Sees Evidence of Colliding Asteroids, ''Astronomy Today'', Feb.2, 2010]
4. [[Carl W. Hergenrother. Hergenrother, Carl W.]]; [http://transientsky.wordpress.com/2010/01/10/the-curious-case-of-comet-linear/ ''The Curious Case of Comet LINEAR''], ''The Transient Sky'', 10 January 2010 (1.8-m telescope on Kitt Peak)
5. [http://comethunter.de/ Catalogue of Comet Discoveries], Comethunter.de
6. (2010). "A recent disruption of the main-belt asteroid P/2010?A2". Nature.
7. (2010). "A collision in 2009 as the origin of the debris trail of asteroid P/2010?A2". Nature.