P/2010 A2 (LINEAR): The 5th Main-Belt Comet

P/2010 A2 (LINEAR): The 5th Main-Belt Comet

Summary
P/2010 A2 is the 5th recognized Main Belt Comet (MBC). It differs from the others in having an orbit within the hot, inner regions of the asteroid belt. The morphology suggests - but does not prove - a recent collisional origin. We cannot rule out the possibility that P/2010 A2 is driven by ice sublimation, as is MBC prototype 133P/Elst-Pizarro, or by an undetermined process.

Caption: Main-belt comet P/2010 A2 imaged at the WIYN 3.5-m telescope on UT 2010 Jan 11 by James Annis (Fermilab), Marcelle Soares-Santos (FermiLab and University of Sao Paulo) and David Jewitt (UCLA). The portion of the image shown is about 3 arcmin in length (140,000 km at the comet). The broad band of light is sunlight scattered from dust apparently emitted from the tiny, point-like object at the head of the comet (indicated by arrows in the right-hand panel). In this image, numerous background stars and galaxies have been largely removed by image processing (a straight median stack, if you want to know).

Main Belt Comets (MBCs)
Main Belt Comets have been known as the third distinct class of comet since 2006 (see the first-listed paper, below). They simultaneously possess

the orbital characteristics of asteroids (specifically, semi major axes less than Jupiter's) AND

Tisserand parameters greater than 3 AND

the physical properties of comets.

Some MBCs, notably the prototype 133P, appear to behave just like comets (e.g. their activity waxes and wains repetitively) and they are thought to be powered by the sublimation of near-surface ice. This ice may be primordial.

Other MBCs could be dust clouds produced by colliding asteroids or by some other surface instability. Future observations may reveal the nature of P/2010 A2. At the moment, it's too early to say.

Papers About MBCs

MBC Class

P/Read

133P/Elst-Pizarro

P/Garradd

David Jewitt

Comet	Jewitt	Kuiper

1,466

--
Good Clear Skies
--
Astrocomet
--
Colin James Watling
--
Real Astronomer and head of the Comet section for LYRA (Lowestoft and Great Yarmouth Regional Astronomers) also head of K.A.G (Kessingland Astronomy Group) and Navigator (Astrogator) of the Stars (Fieldwork)
--
Web: http://lyra.freewebsites.com/