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C. A. Beichman, G. Bryden, M. Werner, K. Stapelfeldt (JPL), G. Rieke, J. Stansberry, D. Trilling, K. Misselt, K. Y. L. Su (Univ. of Arizona)
We've used the InfraRed Spectrograph (IRS) on the Spitzer Space Telescope to examine a sample of 45 F5-K5 main-sequence dwarf stars, looking for emission above the stellar photosphere. The three modules used (Short-Low 1, Long-Low 1, and Long-Low 2) cover each stellar spectra from 8 to 35 um. Observations made during the first six months of Spitzer's mission have been reduced with careful flat-fielding in order to remove residual pixel-to-pixel calibration problems down to <3%. In most cases, the lack of a detected excess rules out the presence of hot (100-1000K) dust at the level of 100-1000 times our zodiacal cloud. Around one star, a nearby K dwarf, we've found prominent dust emission indicative of small, crystalline grains that must be located within 1 AU of the star. We will discuss possible asteroidal or cometary origins for this dust.
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.