Visible and Near Infrared Spectroscopic and Spectrophotometric Observations of NEOs

de Leon Cruz, J.; Licandro, J.; Serra-Ricart, M.
Bibliographical reference

American Astronomical Society, DPS meeting #35, #34.07; Bulletin of the American Astronomical Society, Vol. 35, p.977

Advertised on:
5
2003
Number of authors
3
IAC number of authors
3
Citations
0
Refereed citations
0
Description
In august 2002 we started an observational program to obtain physical information of a significant number of Near Earth Objects by means of simultaneous visible and near infrared spectroscopy and spectrophotometry using telescope facilities of Teide and El Roque de los Muchachos Observatories (Canary Islands, Spain). Near infrared spectroscopy is done using the 3.5-m TNG telescope with the NICS camera-spectrograph and its low resolution Amici prism disperser (Licandro et al. 2001, A&A 373, 29L). Visible spectroscopy is done using the 2.5-m NOT telescope with the ALFOSC camera-spectrograph. At present we have some spectra taken with both telescopes, and 4 nights schedulled for simultaneous observations next semester. Simultaneous visible and near-infrared photometry is done using the CCD camera attached to the 80-cm IAC80 telescope and B,V,R,I filters, and the 1.5-m Carlos Sanchez Telescope with CAIN camera (Nicmos 256x256 array) and J,H,K filters. Until this moment we have spent almost 50 nights for the photometric program, and schedulled 4 nights per month next semester. Our spectral analysis at visible wavelengths of these objects uses some of the techniques and taxonomic system developed by Bus (1999, PhD thesis), studying the presence or absence of specific spectral features in their reflectance spectra. In addition, near infrared spectra obtained for a number of NEOs enhances the compositional interpretation of our sample. Broad band spectrophotometric colors also provide low resolution spectra that can be compared with taxonomic classes defined by Tholen (1984, PhD Thesis). We also compare our spectral data with laboratory measurements of meteorites (Gaffey 1976, JGR 81,905) in order to stablish a possible link between main belt asteroids, near-Earth objects and meterorites, and to detect the effects of space weathering in the surface composition of our objects. A description of the program and preliminary results is presented.