MSX Observations of Cometary Dust

R. G. Walker (VRI), D. J. Lein (Bucknell Univ.), S. Jayaraman, E. A. Barker (VRI), S. D. Price (AFRL)

We report preliminary results of observations in four infrared bands from 6.8 to 25 microns of comets Hyakutake, Tabur and Hale-Bopp obtained by the Midcourse Space Experiment (MSX) satellite. The line scanned arrays in the infrared telescope have a resolution of 18 arc seconds. MSX observed eight comets, but these are the three that have been examined to date. Each comet observation includes 15 scans along the comet's orbit ( tex2html_wrap_inline11 wide by tex2html_wrap_inline13 long). The large field scanned combined with the good sensitivity of the detectors and the factor of four co-add advantage from the 15 scans allows us to map the dust to great distances from the comet. Preliminary images are presented and interpreted in terms of dust production rate, emission mechanism, and grain properties by comparison to theoretical models of the dust distribution.