AVAST survey 0.4-1.0μm spectroscopy of igneous asteroids in the inner and middle main belt

摘要

We present the spectra of 60 asteroids, including 47. V-types observed during the first phase of the Adler V-Type Asteroid (AVAST) Survey. SDSS photometry was used to select candidate V-type asteroids for follow up by nature of their very blue i- z color. 47 of the 61 observed candidates were positively classified as V-type asteroids, while an additional six show indications of a 0.9μm feature consistent with V-type spectra, but not sufficient for formal classification. Four asteroids were found to be S-type, all of which had i-z values very near the adopted AVAST selection criteria of i-z.-0.2, including one candidate observed well outside the cut (at a mean i-z of -0.11). Three A-type asteroids were also identified. Six V-type asteroids were observed beyond the 3:1 mean motion resonance with Jupiter, including the identification of two new V-type asteroids (63085 and 105041) at this distance. Six V-type asteroids were observed with low (<5°) orbital inclination, outside of the normal dynamical range of classic Vestoids, and are suggestive of a non-Vesta origin for at least some of the population.