Spectral analysis and mineralogical characterization of 11 olivine–pyroxene rich NEAs Original Research Article

We present visible and near-infrared spectra (0.5–2.4 μm) of 11 Near Earth Asteroids obtained with the telescopes at the “Observatorio del Roque de los Muchachos” in La Palma, Spain. A spectral analysis of the obtained data is performed in order to establish the taxonomical classification of the observed asteroids. We use the method outlined by Cloutis et al. [Cloutis, E.A., Gaffey, M.J., Jackowski, T.L. Calibrations of phase abundance, composition, and particle size distribution for olivine-orthopyroxene mixtures from reflectance spectra. J. Geophys. Res. 91, B11, 11641–11653, 1986] and Gaffey et al. [Gaffey, M.J., Bell, J.F., Brown, R.H. Mineralogical variations within the S-type asteroid class. Icarus 106, 573–602, 1993] to obtain spectral parameters that provide us with information about their surface composition. We found 2 V-type asteroids and 9 S-type asteroids, including several compositional subtypes.We also use the Modified Gaussian Model (MGM) method developed by Sunshine et al. [Sunshine, J.M., Pieters, C.M., Pratt, S.F. Deconvolution of mineral absorption bands: an improved approach. J. Geophys. Res. 95, B5, 6955–6966, 1990] to extract further mineralogical information from the spectra of two of these asteroids, those classified as V-type. We obtain a surface compositional proportion of about 70% of orthopyroxene and 30% of clinopyroxene for both asteroids.