Shape and spin determination of Barbarian asteroids
Abstract
Context. The so-called Barbarian asteroids share peculiar, but common polarimetric properties, probably related to both their shape and composition. They are named after (234) Barbara, the first on which such properties were identified. As has been suggested, large scale topographic features could play a role in the polarimetric response, if the shapes of Barbarians are particularly irregular and present a variety of scattering/incidence angles. This idea is supported by the shape of (234) Barbara, that appears to be deeply excavated by wide concave areas revealed by photometry and stellar occultations. Aims. With these motivations, we started an observation campaign to characterise the shape and rotation properties of Small Main- Belt Asteroid Spectroscopic Survey (SMASS) type L and Ld asteroids. As many of them show long rotation periods, we activated a worldwide network of observers to obtain a dense temporal coverage. Methods. We used light-curve inversion technique in order to determine the sidereal rotation periods of 15 asteroids and the con- vergence to a stable shape and pole coordinates for 8 of them. By using available data from occultations, we are able to scale some shapes to an absolute size. We also study the rotation periods of our sample looking for confirmation of the suspected abundance of asteroids with long rotation periods. Results. Our results show that the shape models of our sample do not seem to have peculiar properties with respect to asteroids with similar size, while an excess of slow rotators is most probably confirmed.
Keywords
Cite
@article{arxiv.1707.07503,
title = {Shape and spin determination of Barbarian asteroids},
author = {M. Devogèle and P. Tanga and P. Bendjoya and J. P. Rivet and J. Surdej and J. Hanus and L. Abe and P. Antonini and R. A. Artola and M. Audejean and R. Behrend and F. Berski and J. G. Bosch and M. Bronikowska and A. Carbognani and F. Char and M. -J. Kim and Y. -J. Choi and C. A. Colazo and J. Coloma and D. Coward and R. Durkee and O. Erece and E. Forne and P. Hickson and R. Hirsch and J. Horbowicz and K. Kamiński and P. Kankiewicz and M. Kaplan and T. Kwiatkowski and I. Konstanciak and A. Kruszewki and V. Kudak and F. Manzini and H. -K. Moon and A. Marciniak and M. Murawiecka and J. Nadolny and W. Ogłoza and J. L Ortiz and D. Oszkiewicz and H. Pallares and N. Peixinho and R. Poncy and F. Reyes and J. A. de los Reyes and T. Santana-Ros and K. Sobkowiak and S. Pastor and F. Pilcher and M. C. Quiñones and P. Trela and D. Vernet},
journal= {arXiv preprint arXiv:1707.07503},
year = {2017}
}