Henry H. Hsieh, Bin Yang, Nader Haghighipour, Heather M. Kaluna, Alan Fitzsimmons, Larry Denneau, Bojan Novakovic, Robert Jedicke, Richard J. Wainscoat, James D. Armstrong, Samuel R. Duddy, Stephen C. Lowry, Chadwick A. Trujillo, Marco Micheli, Jacqueline V. Keane, Laurie Urban, Timm Riesen, Karen J. Meech, Shinsuke Abe, Yu-Chi Cheng, Wen-Ping Chen, Mikael Granvik, Tommy Grav, Wing-Huen Ip, Daisuke Kinoshita, Jan Kleyna, Pedro Lacerda, Tim Lister, Andrea Milani, David J. Tholen, Peter Veres, Carey M. Lisse, Michael S. Kelley, Yanga R. Fernandez, Bhuwan C. Bhatt, Devendra K. Sahu, Nick Kaiser, K. C. Chambers, Klaus W. Hodapp, Eugene A. Magnier, Paul A. Price, John L. Tonry
Main belt asteroid (300163) 2006 VW139 (later designated P/2006 VW139) was
discovered to exhibit comet-like activity by the Pan-STARRS1 survey telescope
using automated point-spread-function analyses performed by PS1's Moving Object
Processing System. Deep follow-up observations show both a short (\sim 10")
antisolar dust tail and a longer (\sim 60") dust trail aligned with the
object's orbit plane, similar to the morphology observed for another main-belt
comet, P/2010 R2 (La Sagra), and other well-established comets, implying the
action of a long-lived, sublimation-driven emission event. Photometry showing
the brightness of the near-nucleus coma remaining constant over \sim 30 days
provides further evidence for this object's cometary nature, suggesting it is
in fact a main-belt comet, and not a disrupted asteroid. A spectroscopic search
for CN emission was unsuccessful, though we find an upper limit CN production
rate of Q_CN < 1.3x10^24 mol/s, from which we infer a water production rate of
Q_H2O < 10^26 mol/s. We also find an approximately linear optical spectral
slope of 7.2%/1000A, similar to other cometary dust comae. Numerical
simulations indicate that P/2006 VW139 is dynamically stable for > 100 Myr,
while a search for a potential asteroid family around the object reveals a
cluster of 24 asteroids within a cutoff distance of 68 m/s. At 70 m/s, this
cluster merges with the Themis family, suggesting that it could be similar to
the Beagle family to which another main-belt comet, 133P/Elst-Pizarro, belongs.
View original:
http://arxiv.org/abs/1202.2126
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