http://arxiv.org/abs/1603.03090
We present the first comprehensive thermal and rotational analysis of the second most distant trans-Neptunian object (225088) 2007 OR10. We combined optical light curves provided by the Kepler space telescope — K2 extended mission and thermal infrared data provided by the Herschel Space Observatory. We found that (225088) 2007 OR10 is likely to be larger and darker than derived by earlier studies: we obtained a diameter of d=1535^{+75}_{-225} km which places (225088) 2007 OR10 in the biggest top three trans-Neptunian objects. The corresponding visual geometric albedo is p_V=0.089^{+0.031}_{-0.009}. The light curve analysis revealed a slow rotation rate of P_rot=44.81+/-0.37 h, superseded by a very few objects only. The most likely light-curve solution is double-peaked with a slight asymmetry, however, we cannot safely rule out the possibility of having a rotation period of P_rot=22.40+/-0.18 h which corresponds to a single-peaked solution. Due to the size and slow rotation, the shape of the object should be a MacLaurin ellipsoid, so the light variation should be caused by surface inhomogeneities. Its newly derived larger diameter also implies larger surface gravity and a more likely retention of volatiles — CH_4, CO and N_2 — on the surface.
A. Pal, C. Kiss, T. Muller, et. al.
Fri, 11 Mar 16
39/59
Comments: Accepted for publication in AJ, 8 pages in emulateapj style
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