The Tempel 2 Dust Trail
Abstract
Observations of cometary dust at visual wavelengths are dominated by particles microns in size. At thermal wavelengths emissions from submillimeter and larger particles become important. Dust trails are phenomena which were first detected by the Infrared Astronomical Satellite (IRAS), and have been identified as large debris covering portions of the orbits of short-period comets. The Tempel 2 Dust Trail was extensively observed by the IRAS. Evidence is presented suggesting that the trail is composed of particles on the order of 1 mm and large in diameter with velocities of several meters per second relative to the parent comet, assuming isotropic emission. Trail particles forward of the comets orbital position have a minimum diameter of approx. 6 mm. These particles were emitted by the nucleus over a few hundred years. Excess color temperatures relative to a blackbody indicate that the particles either are large enough to support a temperature gradient over their surfaces or that a small particle population exists with diameters < 100A. In the case of the latter, such small particles would have to have originated from the large particles, otherwise their acceleration by the gas outflow to km/s velocities would have prevented their ejection into trail orbits. (edc)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 28, 1989
- Accession Number
- ADA224395
Entities
People
- D. J. Lien
- M. V. Sykes
- R. G. Walker