Bibcode
Duffard, R.; Lazzaro, D.; Licandro, J.; De Sanctis, M. C.; Capria, M. T.; Carvano, J.
Bibliographical reference
35th COSPAR Scientific Assembly. Held 18 - 25 July 2004, in Paris, France., p.408
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2004
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Description
Asteroid (4) Vesta is known as the unique large object of the main belt
showing a basaltic crust and is a target of the NASA Dawn Mission. Vesta
composition is also similar to that of basaltic achondrite meteorites,
specifically the Eucrites, Diogenites and Howardites (HED). On the other
hand, in recent taxonomies, asteroids showing a spectrum similar to that
of Vesta have been classified as V-type. The spectroscopic link between
the V-type asteroids in the vicinity of Vesta, in near-Earth orbits, and
the HED meteorites seems to be quite consistent, especially if we take
into account that basaltic material is very rare in the asteroid belt.
The depth, width and spectral placement of the 1- and 2-micron mafic
silicate absorption features in the reflectance spectrum of Vesta and
V-type asteroids help to characterize the surface mineralogy of these
objects. We present reflectance spectra of 19 V-type asteroids obtained
at the 3.6 m Telescopio Nazionale Galileo covering 0.8 to 2.5 microns.
For 8 of these asteroids we obtained also visible spectra in the same
observational run. The range from 0.8 to 2.5 microns, encompassing the 1
and 2 microns pyroxene features, allows a precise mineralogical
characterization of these asteroids. Our results on the mineralogy of
V-type asteroids in the neighbourhood of Vesta corroborate previous
works about the existence of different kinds of basalts at the same time
that do not show any clear correlation between mineralogies and the
objects being, or not, members of the Vesta's dynamical family. The
obtained data suggests the possible coexistence of distinct
mineralogical groups among the V-type asteroids, either probing
differents layers of (4) Vesta or coming from different bodies. "Based
on observations made with the Italian Telescopio Nazionale Galileo (TNG)
operated on the island of La Palma by the Centro Galileo Galilei of the
INAF (Istituto Nazionale di Astrofisica) at the Spanish
Observatório del Roque de los Muchachos of the Instituto de
Astrofísica de Canarias"