Photometric observations of a very young family-member asteroid (832) Karin

Abstract

The asteroid (832) Karin is the largest member of the Karin family, which is thought to have been formed by a catastrophic collision 5.8 Myr ago. We performed photometric observations of Karin from 2003 July to September, and we report here on its lightcRurve and colors in several visible bands. The rotational synodic period of Karin was determined to be 18.35 ± 0.02 hr. Its absolute magnitude (H) and the slope parameter (G) of the solar phase curve were 11.49 ± 0.02 and 0.19 ± 0.04, respectively. Based on our color observations, we confirmed that Karin is an S-type asteroid. In addition, we found that there is likely to be a color variation over the surface of Karin. We infer that the color variation is due to the difference between the fresh surface, excavated by the family-forming disruption, and the weathered surface, exposed to space radiation and particle bombardment over a long period.