The non-convex shape of (234) Barbara, the first Barbarian
Abstract
Asteroid (234) Barbara is the prototype of a category of asteroids that has been shown to be extremely rich in refractory inclusions, the oldest material ever found in the Solar System. It exhibits several peculiar features, most notably its polarimetric behavior. In recent years other objects sharing the same property (collectively known as "Barbarians") have been discovered. Interferometric observations in the mid-infrared with the ESO VLTI suggested that (234) Barbara might have a bi-lobated shape or even a large companion satellite. We use a large set of 57 optical lightcurves acquired between 1979 and 2014, together with the timings of two stellar occultations in 2009, to determine the rotation period, spin-vector coordinates, and 3-D shape of (234) Barbara, using two different shape reconstruction algorithms. By using the lightcurves combined to the results obtained from stellar occultations, we are able to show that the shape of (234) Barbara exhibits large concave areas. Possible links of the shape to the polarimetric properties and the object evolution are discussed. We also show that VLTI data can be modeled without the presence of a satellite.
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Cite
@article{arxiv.1502.00460,
title = {The non-convex shape of (234) Barbara, the first Barbarian},
author = {P. Tanga and B. Carry and F. Colas and M. Delbo and A. Matter and J. Hanus and V. Ali Lagoa and A. H. Andrei and M. Assafin and M. Audejean and R. Behrend and J. I. B. Camargo and A. Carbognani and M. Cedres Reyes and M. Conjat and N. Cornero and D. Coward and R. Crippa and E. de Ferra Fantin and M. Devogele and G. Dubos and E. Frappa and M. Gillon and H. Hamanowa and E. Jehin and A. Klotz and A. Kryszczynska and J. Lecacheux and A. Leroy and J. Manfroid and F. Manzini and L. Maquet and E. Morelle and S. Mottola and M. Polinska and R. Roy and M. Todd and F. Vachier and C. Vera Hernandez and P. Wiggins},
journal= {arXiv preprint arXiv:1502.00460},
year = {2015}
}
Comments
10 pages, 6 figures