Year: 2015
Type: article
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 behaviour. 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 (Very Large Telescope Interferometer) suggested that (234) Barbara might have a bi-lobated shape or even a large companion satellite. We use a large set of 57 optical light curves 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 light curves 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 modelled without the presence of a satellite.
DOI: 10.1093/mnras/stv229
Authors: P. Tanga, B. Carry, F. Colas, M. Delbo, A. Matter, J. Hanuš, V. Alí Lagoa, A. H. Andrei, M. Assafin, M. Audejean, R. Behrend, J. I. B. Camargo, A. Carbognani, M. Cedrés Reyes, M. Conjat, N. Cornero, D. Coward, R. Crippa, E. de Ferra Fantin, M. Devogéle, G. Dubos, E. Frappa, M. Gillon, H. Hamanowa, E. Jehin, A. Klotz, A. Kryszczyńska, J. Lecacheux, A. Leroy, J. Manfroid, F. Manzini, L. Maquet, E. Morelle, S. Mottola, M. Polińska, R. Roy, M. Todd, F. Vachier, C. Vera Hernández, P. Wiggins
Institutions: Centre National de la Recherche Scientifique, Lagrange Laboratory, Observatoire de la Côte d’Azur, Observatoire de Paris, Institut de Mécanique Céleste et de Calcul des Éphémérides, Max Planck Institute for Radio Astronomy, Charles University, Universidade Federal do Rio de Janeiro, Valongo Observatory, National Observatory, Systèmes de Référence Temps-Espace, Laboratoire Temps Espace, University of Geneva, Osservatorio Astronomico della Regione Autonoma Valle d'Aosta, Regione Autonoma Valle d'Aosta, Curtin University, University of Liège, Institut de Recherche en Astrophysique et Planétologie, Adam Mickiewicz University in Poznań, Laboratoire d’études spatiales et d’instrumentation en astrophysique, Université Paris Diderot, Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR), Teledyne Technologies (France)
Language: English
Topic: Astro and Planetary Science
Subfield: Space and Planetary Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1985229758