Bibcode
de Leon, J.; Duffard, R.; Licandro, J.; Lazzaro, D.
Referencia bibliográfica
35th COSPAR Scientific Assembly. Held 18 - 25 July 2004, in Paris, France., p.1155
Advertised on:
0
2004
Número de citas
0
Número de citas referidas
0
Descripción
A-type asteroids are usually found in the main asteroid belt and their
spectra are very similar to spectra of the silicate mineral olivine
(Cruikshank and Hartmann 1984). The existence of olivine-rich asteroids
is a result of differentiation, those being the pieces of the mantle of
a larger parent body. Extraterrestrial sources of such material must
exist because we have meteorites that are nearly pure olivine (dunites).
There is a limited number of observed asteroids classified as A-type,
all of them belonging to the Main Belt and the study of such objects is
crucial to better understand their origin and formation and their
relation with dunites. We have obtained visible and near infrared
reflectance spectra of asteroid (1951) Lick using the telescopes located
at Observatorio del Roque de los Muchachos (Canary Islands, Spain).
According to its spectral characteristics in the visible region, this
object has been classified as an A-type asteroid by Bus and Binzel
(2002). Although considered an Amor object by several authors, according
to its orbital parameters (a = 1.390 AU, e = 0.061, i = 39.093 deg, q =
1.304) this object is just in the limit that separates Amors from Mars
Crossers (q = 1.3). Whether it is classified as an Amor or a Mars
Crosser, (1951) Lick is the first object with such orbital
characteristics classified as an A-type asteroid. Here we present a
mineralogical analysis of the reflectance spectra obtained for (1951)
Lick. We calculate several parameters that are extracted from the
spectrum of the asteroid and that give relevant information about its
mineralogical composition, using the method defined by Gaffey et al.
(1993). We also present results obtained by a preliminary fit to the
absorption band associated to the presence of the olivine mineral using
the Modified Gaussian Model method (MGM) developed by Sunshine et
al.(1990). References Bus, J. S. and Binzel, R. P. 2002. Icarus, 158,
146 Cuikshank, D. P. and Hartmann, W. K. 1984. Science, 223, 281 Gaffey,
M. J., Bell, J. F., Brown, R. H., Burbine, T. H., Piatek, J. L., Reed,
K. L. and Chaky, D. A. 1993. Icarus, 106, 573 Sunshine, J. M., Pieters,
C. M. and Pratt, S. F. 1990. JGR, 95, B5, 6955