Spectroscopy of X-Type Asteroids

Abstract

Infrared observations (0.8-2.5 μm) of 42 asteroids in the X complex are presented. Previous studies of these asteroids and their taxonomic classes are summarized using both the Tholen and the Bus-Binzel taxonomic systems. With this study we seek to extend our compositional information about X-complex asteroids in order to refine our knowledge of the geologic structure of the asteroid regions. Our results suggest that there may be a type of material among X-complex objects that is not related to E-, M-, or P-type object material. This, in turn, suggests that albedo should not be the only criterion for a mineralogy-based subclassification of X-complex objects.