Physical characterization of the Karin family

¹ LESIA, Observatoire de Paris, 92195 Meudon Principal Cedex, France e-mail: pierre.vernazza@obspm.fr
² IMCCE, Observatoire de Paris, 77 Av. Denfert Rochereau, 75014 Paris Cedex, France
³ Spaceflight Dynamics Section, ISTI-CNR, via Moruzzi, 1, 56124 Pisa, Italy
⁴ INAF, Osservatorio Astronomico di Roma, via Frascatti 33, 00040 Monteporzio Catone (Roma), Italy
⁵ Southwest Research Institute, 1050 Walnut St. Suite 400, Boulder, CO 80302, USA
⁶ Dipartimento di Fisica, Universitá di Lecce, via Arnesano, 73100, Lecce, Italy
⁷ CISAS-Astronomy Dep., Padova University, vicolo dell'Osservatorio, 2, 35122 Padova, Italy

Received: 8 June 2006
Accepted: 8 September 2006

Abstract

Aims.The Karin cluster is a small asteroid family that formed  Myr ago in the outer main belt. This is an exceptionally young age for an asteroid family. To investigate the composition and homogeneity of the members of this family, we started a spectroscopic survey in the visible and in the near-IR.

Methods.We observed 24 Karin asteroid members in the visible and 6 members in the near-IR.

Results.In the visible range, all the objects share the same characteristics: a maximum around μm, and a spectral slope spanning a continuous but limited range; in the NIR, our spectra show a similar behaviour. Our results suggest global homogeneity of the parent body and none of the investigated objects seems to be an interloper. These results are consistent with the dynamical hypothesis of a common origin. Finally, the range of spectral slopes is similar with the range of slopes for OC meteorites. We interpret this result as an indication of a low degree of spatial alteration for the observed surfaces. This result is coherent with the young age of the family.