Spectral characterization of V-type asteroids outside the Vesta family

Abstract

We present new near-infrared (NIR) reflectance spectra of 10 V-type candidate asteroids obtained at the 3.6 m Telescopio Nazionale Galileo covering the spectral range of 0.7-2.5 μm. The observed objects were selected from diverse data sets of putative V-type asteroids in order to characterize them, and hence better understand their relationship with (4) Vesta. We derive spectral parameters from NIR spectra to infer mineralogical information of the observed asteroids. All the spectra of the asteroids here reported show two prominent absorption features at 1 and 2 μm that are typical of V-class objects. The comparison of spectral parameters such as band centres and band separation, among our observations, Howardites, Eucrites, Diogenites meteorites, and (4) Vesta from Visible and Infrared Spectrometer (VIR) data on Dawn reveals that there is a strong correlation between these objects. From our analysis, four objects are compatible with Howardites, three are more similar to a eucritic-like composition, and two are compatible with Diogenites. Asteroid 26145, which is the only member of the Vesta dynamical family observed in 2012 March, is compatible with Vesta's surface, and shows a composition close to the Eucrites.