Spectral characterization of V-type asteroids - II. A statistical analysis

TL;DR

This study performs a statistical analysis of 190 spectra from 117 V-type asteroids to investigate their origins, revealing that most inner main belt V-types are linked to Vesta, unlike those in the middle and outer belts.

Contribution

It provides a comprehensive spectral comparison of V-type asteroids across the main belt, highlighting their potential diverse origins beyond Vesta.

Findings

Most inner main belt V-types are consistent with Vesta origin.

V-types in middle and outer main belt likely have different sources.

Spectral properties vary with dynamical groupings.

Abstract

In recent years several small basaltic V-type asteroids have been identified all around the main belt. Most of them are members of the Vesta dynamical family, but an increasingly large number appear to have no link with it. The question that arises is whether all these basaltic objects do indeed come from Vesta. To find the answer to the above questioning, we decided to perform a statistical analysis of the spectroscopic and mineralogical properties of a large sample of V-types, with the objective to highlight similarities and differences among them, and shed light on their unique, or not, origin. The analysis was performed using 190 visible and near-infrared spectra from the literature for 117 V-type asteroids. The asteroids were grouped according to their dynamical properties and their computed spectral parameters compared. Comparison was also performed with spectral parameters of a sample of HED meteorites and data of the surface of Vesta taken by the VIR instrument on board of the Dawn spacecraft. Our analysis shows that although most of the V-type asteroids in the inner main belt do have a surface composition compatible with an origin from Vesta, this seem not to be the case for V-types in the middle and outer main belt.