Monday, February 13, 2012

1202.2126 (Henry H. Hsieh et al.)

Discovery of Main-Belt Comet P/2006 VW139 by Pan-STARRS1    [PDF]

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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