The Near-IR Spectrocopy of Two M-Class Main Belt Asteroids, 418 Alemannia and 504 Cora (original) (raw)
NASA/ADS
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Abstract
418 Alemannia and 504 Cora are two M-class main belt asteroids (Tholen, 1984, 1989) that were observed as part of a comprehensive NIR spectral survey of the main-belt M-class population. Previous studies of M-class asteroids show that while some are spectrally featureless, most exhibit weak 1- and/or 2-micron absorption features that suggest the presence of mafic silicate or oxides minerals such as pyroxene(s), olivine, or spinels. The presence of NiFe metal is often inferred in addition to silicate minerals. Potential meteorite analogs include pallasites, mesosiderites and CO/CV chondrites, although many M-asteroids do not have clear meteorite analogs. Hardersen et al. (2005, 2006, 2007) has discovered significant spectral, mineralogic, and geologic diversity among 28 of the 40 M-class asteroids studied thus far. NIR spectroscopic observations of 418 Alemannia and 504 Cora were collected using the NASA Infrared Telescope Facility / SpeX on Mauna Kea, Hawai'I from January 22-24, 2007 UT. NIR spectra of 418 Alemannia display a weak 0.9 micron absorption feature superimposed on an overall reddish spectrum. The average NIR spectrum of 504 Cora exhibits weak 0.9- and 1.9-micron absorption features, suggestive of the presence of surficial pyroxene. A thorough spectral, mineralogic, and dynamical analysis of these asteroids will be presented along with suggestions of any potential meteorite analog. This research is generously supported by NASA Planetary Astronomy Grant NNG05GH01G.
Publication:
AAS/Division for Planetary Sciences Meeting Abstracts #39
Pub Date:
October 2007
Bibcode: