Discovery of Main-belt Comet P/2006 VW139 by Pan-STARRS1

March 2012 • 2012ApJ...748L..15H

Authors • Hsieh, Henry H. • Yang, Bin • Haghighipour, Nader • Kaluna, Heather M. • Fitzsimmons, Alan • Denneau, Larry • Novaković, Bojan • Jedicke, Robert • Wainscoat, Richard J. • Armstrong, James D. • Duddy, Samuel R. • Lowry, Stephen C. • Trujillo, Chadwick A. • Micheli, Marco • Keane, Jacqueline V. • Urban, Laurie • Riesen, Timm • Meech, Karen J. • Abe, Shinsuke • Cheng, Yu-Chi • Chen, Wen-Ping • Granvik, Mikael • Grav, Tommy • Ip, Wing-Huen • Kinoshita, Daisuke • Kleyna, Jan • Lacerda, Pedro • Lister, Tim • Milani, Andrea • Tholen, David J. • Vereš, Peter • Lisse, Carey M. • Kelley, Michael S. • Fernández, Yanga R. • Bhatt, Bhuwan C. • Sahu, Devendra K. • Kaiser, Nick • Chambers, K. C. • Hodapp, Klaus W. • Magnier, Eugene A. • Price, Paul A. • Tonry, John L.

Abstract • The main-belt asteroid (300163) 2006 VW139 (later designated P/2006 VW139) was discovered to exhibit comet-like activity by the Pan-STARRS1 (PS1) survey telescope using automated point-spread-function analyses performed by PS1's Moving Object Processing System. Deep follow-up observations show both a short (~10'') antisolar dust tail and a longer (~60'') dust trail aligned with the object's orbit plane, similar to the morphology observed for another main-belt comet (MBC), 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 ~30 days provides further evidence for this object's cometary nature, suggesting it is in fact an MBC, 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 < 1.3 × 1024 mol s-1, from which we infer a water production rate of Q_H_2O<10^{26} mol s-1. We also find an approximately linear optical spectral slope of 7.2%/1000 Å, 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-1. At 70 m s-1, this cluster merges with the Themis family, suggesting that it could be similar to the Beagle family to which another MBC, 133P/Elst-Pizarro, belongs.


IPAC Authors

Laurie Chu

Postdoctoral Research Associate