Spectral properties of eight near-Earth asteroids

Context. Near-Earth objects are among the most accessible bodies in the solar system in terms of the spacecraft propulsion requirements to reach them. The choice of targets and the planning of space missions are based on high quality ground-based science. Aims. The knowledge of the ensemble of physical parameters for these objects, including their composition, is a critical point in defining any mission scientific objectives. Determining the physical properties of near-Earth asteroids (NEAs) is also possible from the ground by analyzing spectroscopy at both visible and infrared wavelengths. Methods. We present spectra of eight NEAs (1917, 8567, 16960, 164400, 188452, 2001 SG286, and 2010 TD54) obtained using the NASA telescope IRTF equipped with the spectro-imager SpeX. The observations were performed in the 0.8-2.5 mu m spectral region using the low resolution mode of the spectrograph. We completed the taxonomic classification using the Bus-DeMeo taxonomy. We analyzed the spectra by comparing them to meteorite spectra from the Relab database using chi(2) approach. For the S-type asteroids of our sample, the band centers and BAR were calculated. We also attempted to interpret our data using a space-weathering model. Results. The taxonomic classification of five objects was reviewed and we assigned a corresponding type to the other three asteroids that were not classified before. We found that (1917) Cuyo, (8567) 1996 HW1, (16960) 1998 QS52, (188452) 2004 HE62, and 2010 TD54 are in the S-complex. We achieved a good matching of our S-type asteroids with the spectra of ordinary chondrites meteorites. The asteroid (5620) Jasonwheeler was found to have a NIR spectrum similar to carbonaceous chondrite meteorites. Thus, our results confirm its primitive properties obtained in several other spectral intervals.