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Coordinated thermal and optical observations of Trans-Neptunian object (20000) Varuna from Sierra Nevada

E. Lellouch·R. Moreno·J. L. Ortiz·G. Paubert·A. Doressoundiram·N. Peixinho
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Abstract

We report on coordinated thermal and optical measurements of trans-Neptunian object (20000) Varuna obtained in January-February 2002, respectively from the IRAM 30-m and IAA 1.5 m telescopes. The optical data show a lightcurve with a period of 3.176+/-0.010 hr, a mean V magnitude of 20.37+/-0.08 and a 0.42+/-0.01 magnitude amplitude. They also tentatively indicate that the lightcurve is asymmetric and double-peaked. The thermal observations indicate a 1.12+/-0.41 mJy flux, averaged over the object's rotation. Combining the two datasets, we infer that Varuna has a mean 1060(+180/-220) km diameter and a mean 0.038(+0.022/-0.010) V geometric albedo, in general agreement with an earlier determination using the same technique.

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E. Lellouch, R. Moreno, J. L. Ortiz, G. Paubert, A. Doressoundiram, N. Peixinho. 2002-06-27. Coordinated thermal and optical observations of Trans-Neptunian object (20000) Varuna from Sierra Nevada. https://doi.org/10.1051/0004-6361%3A20020903

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