Visible and near-infrared spectroscopic investigation of near-Earth objects at ESO: first results☆

Near-Earth objects (NEOs) represent one of the most intriguing populations of Solar System bodies. These objects appear heterogeneous in all aspects of their physical properties, like shapes, sizes, spin rates, compositions etc. Moreover, as these objects represent also a real threat to the Earth, a good knowledge of their properties and composition is the necessary first step to evaluate mitigation techniques and to understand their origin and evolution. In the last few years we have started a long-term spectroscopic investigation in the visible and near-infrared (NIR) region of near-Earth objects. The observations have been performed with the 3.5 m NTT of the European Southern Observatory of La Silla (Chile). The data presented here are a set of 24 spectra, 14 of which are both visible and NIR. We discuss the taxonomic classification of the observed NEOs, resulting in 13 S-type objects, 1 Q-type, 2 K-types, 3 C-types, 5 Xe-types (two of these, (3103) Eger and (4660) Nereus, are already known as E-types). Moreover, we discuss their links with meteorites and the possible influences of space weathering.

[1]  1993 VW: an ordinary chondrite-like near-Earth asteroid. , 1995 .

[2]  Richard P. Binzel,et al.  Phase II of the Small Main-Belt Asteroid Spectroscopic Survey: The Observations , 2002 .

[3]  R. Binzel,et al.  Spectral Properties of Near-Earth Asteroids: Evidence for Sources of Ordinary Chondrite Meteorites , 1996, Science.

[4]  T. Hiroi,et al.  Importance of space weathering simulation products in compositional modeling of asteroids: 349 Dembowska and 446 Aeternitas as examples , 2001 .

[5]  M. Bailey,et al.  Dynamical evolution of cometary asteroids , 1998 .

[6]  Richard P. Binzel,et al.  Phase II of the Small Main-Belt Asteroid Spectroscopic Survey: A Feature-Based Taxonomy , 2002 .

[7]  Richard P. Binzel,et al.  Asteroid spectroscopy: Progress and perspectives , 1993 .

[8]  Richard P. Binzel,et al.  Spectral Properties of Near-Earth Objects: Palomar and IRTF Results for 48 Objects Including Spacecraft Targets (9969) Braille and (10302) 1989 ML , 2001 .

[9]  Michael J. Gaffey,et al.  Spectral reflectance characteristics of the meteorite classes , 1976 .

[10]  G. Hahn,et al.  Physical Properties of Near-Earth Objects , 2002 .

[11]  B. Clark,et al.  K asteroids and CO3/CV3 chondrites , 2001 .

[12]  D. J. Tholen,et al.  Asteroid taxonomic classifications , 1989 .

[13]  Gretchen Benedix,et al.  Spectra of extremely reduced assemblages: Implications for Mercury , 2002 .

[14]  D. Tholen,et al.  Asteroid Taxonomy from Cluster Analysis of Photometry. , 1984 .

[15]  Schelte J. Bus,et al.  Compositional structure in the asteroid belt: Results of a spectroscopic survey , 1999 .

[16]  M. Martino,et al.  COMPOSITIONAL PROPERTIES OF NEAR-EARTH ASTEROIDS : SPECTROSCOPIC COMPARISON WITH ORDINARY CHONDRITE METEORITES , 1997 .

[17]  S. Fornasier,et al.  E-Type Asteroids: Spectroscopic Investigation on the 0.5μm Absorption Band☆ , 2001 .