James M. Bauer, A. K. Mainzer, Tommy Grav, Russell G. Walker, Joseph R. Masiero, Erin K. Blauvelt, Robert S. McMillan, Yan R. Fernández, Karen J. Meech, Carey M. Lisse, Roc M. Cutri, John W. Dailey, David J. Tholen, Timm Riesen, Laurie Urban, Alain Khayat, George Pearman, James V. Scotti, Emily Kramer, De'Andre Cherry, Thomas Gautier, Stephanie Gomillion, Jessica Watkins, Edward L. Wright, the WISE Team
We report results based on mid-infrared photometry of 5 active main belt
objects (AMBOs) detected by the Wide-field Infrared Survey Explorer (WISE)
spacecraft. Four of these bodies, P/2010 R2 (La Sagra), 133P/Elst-Pizarro,
(596) Scheila, and 176P/LINEAR, showed no signs of activity at the time of the
observations, allowing the WISE detections to place firm constraints on their
diameters and albedos. Geometric albedos were in the range of a few percent,
and on the order of other measured comet nuclei. P/2010 A2 was observed on
April 2-3, 2010, three months after its peak activity. Photometry of the coma
at 12 and 22 {\mu}m combined with ground-based visible-wavelength measurements
provides constraints on the dust particle mass distribution (PMD), dlogn/dlogm,
yielding power-law slope values of {\alpha} = -0.5 +/- 0.1. This PMD is
considerably more shallow than that found for other comets, in particular
inbound particle fluence during the Stardust encounter of comet 81P/Wild 2. It
is similar to the PMD seen for 9P/Tempel 1 in the immediate aftermath of the
Deep Impact experiment. Upper limits for CO2 & CO production are also provided
for each AMBO and compared with revised production numbers for WISE
observations of 103P/Hartley 2.
View original:
http://arxiv.org/abs/1112.3099
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