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D. Lazzaro, R. Duffard (Observatorio Nacional, Brazil), J. de Leon (IAC, Spain), J. Licandro (ING/IAC, Spain)
Basaltic asteroids, classified as V-type in all taxonomies, are quite rare among the asteroid population. They are spectrally similar to 4 Vesta and to the basaltic achondrite meteorites, specifically the Eucrites, the Diogenites and the Howardites, known as HED meteorites. It has been suggested that all these objects, V-type asteroids and HED meteorites, are genetically linked to Vesta.
In a previous work we investigated the mineralogy of several V-type asteroids in the neighborhood of Vesta (Duffard et al. 2004) showing that the distribution of their spectral parameters is rather distinct from that of HED meteorites as given by Gaffey et al. (1993). The sample of basaltic asteroids analyzed was then increased with the observation of three V-type Near Earth Asteroids. The reflectance spectra of these objects were obtained at the 3.6m Telescopio Nazionale Galileo (TNG) and at the 2.5m Nordic Optical Telescope (NOT) covering the near-infrared and visible range, respectively. Spectral parameters were then obtained using two methods as described in Gaffey et al. (2002) and Sunshine et al. (1990).
We also performed similar analysis on a sample of HED meteorites consisting of 29 Eucrites, 14 Howardites and 10 Diogenites whose spectra were taken from the RELAB public database at Brown University. This resulted in a new definition of the spectral parameter space for the HED meteorites, slightly different from that given by Gaffey et al. (1993). However, when we plot the parameters computed for the sample of V-type asteroids, those near Vesta and those in Near-Earth orbits, we note a greater spread of values, most of them outside the HED region. This result will be discussed on view of its implication on the possible genetic link between V-type asteroids and HED meteorites.
This work has been supported by CNPq and FAPERJ.
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Bulletin of the American Astronomical Society, 36 #4
© 2004. The American Astronomical Soceity.