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Session 42 - Solar Systems.
Display session, Tuesday, January 16
North Banquet Hall, Convention Center
We present the preliminary results of an ongoing spectroscopic survey of near-Earth objects. To date, low-resolution CCD reflectance spectra covering the wavelength range 0.38--1 \mum have been obtained for 15 near-Earth asteroids and three cometary candidates, using the Double Imaging Spectrograph on the Apache Point Observatory 3.5-m telescope. Spectra have also been taken of two well-studied main-belt asteroids for comparison with published work.
The presence of diagnostic solid-state absorption features in most of the spectra permit the examination of these objects' surface mineralogies. Goals of the study include searching for compositional relationships between near-Earth objects and possible source regions in the main asteroid belt, and the identification of plausible parent bodies for specific meteorite types. Since extinct or inactive comets may form a significant fraction of the near-Earth object population, we also examine the spectra for emission features characteristic of cometary volatiles.
Significant spectral differences are noted between some of the observed objects and main-belt asteroids of otherwise similar taxonomic type. For example, the asteroid 2062 Aten is seen to have a deeper 0.9 \mum absorption band and a lower reflectivity at \sim 0.7 \mum than the typical S-type asteroid. This may indicate a more pyroxene or olivine-rich surface, less regolith (more bare rock), larger particle sizes in the regolith, or some combination of all of these influences. No cometary emission features are observed for any of these objects.
Program listing for Tuesday