Title

Near-infrared spectroscopic survey of B-type asteroids: Compositional analysis

Authors

Authors

J. de Leon; N. Pinilla-Alonso; H. Campins; J. Licandro;G. A. Marzo

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

Icarus

Keywords

Spectroscopy; Asteroids, Composition; Meteorites; CARBONACEOUS CHONDRITES; MAIN-BELT; THERMAL METAMORPHISM; REFLECTANCE; SPECTRA; PHASE-II; MU-M; SURFACE; MINERALS; FAMILIES; OBJECTS; Astronomy & Astrophysics

Abstract

We present near-infrared spectra of 23 B-type asteroids obtained with the NICS camera-spectrograph at the 3.56 m Telescopio Nazionale Galileo. We also compile additional visible and near-infrared spectra of another 22 B-type asteroids from the literature. A total of 45 B-types are analyzed. No significant trends in orbital properties of our sample were detected when compared with all known B-types and all known asteroids. The reflectance spectra of the asteroids in the 0.8-2.5 mu m range show a continuous shape variation, from a monotonic negative (blue) slope to a positive (red) slope. This continuous spectral trend is filling the gap between the two main groups of B-types published by Clark et al. ([2010]. J. Geophys. Res., 115, 6005-6027). We found no clear correlations between the spectral slope and the asteroids' sizes or heliocentric distances. We apply a clustering technique to reduce the volume of data to six optimized "average spectra" or "centroids", representative of the whole sample. These centroids are then compared against meteorite spectra from the RELAB database. We found carbonaceous chondrites as the best meteorite analogs for the six centroids. There is a progressive change in analogs that correlates with the spectral slope: from CM2 chondrites (water-rich, aqueously altered) for the reddest centroid, to CK4 chondrites (dry, heated/thermally altered) for the bluest one. (C) 2011 Elsevier Inc. All rights reserved.

Journal Title

Icarus

Volume

218

Issue/Number

1

Publication Date

1-1-2012

Document Type

Article

Language

English

First Page

196

Last Page

206

WOS Identifier

WOS:000301637700015

ISSN

0019-1035

Share

COinS