IRAS IMAGES OF COMET TEMPEL-2

We present the first of 13 sets of observations of periodic Comet Tempel 2 obtained by the Infrared Astronomical Satellite (IRAS). The images taken on UT 1983 August 28 at the four IRAS bandpasses (12, 25, 60 and 100 μm) have been restored to remove instrumental effects. In order to interpret the spatial structure in these infrared images we have compared them with a series of theoretical models based on different dust properties. We conclude that the outer dust coma of this comet is dominated by intermediate size particles (on the order of several millimeters, assuming a density of 1 g cm-3). A population of even larger particles forms the portion of the "dust trail" seen in these images. Comet Tempel 2 appears to be richer in large dust grains than othercomets observed with similar infrared imaging techniques from the ground. © 1990.