Imaging of Comet 21P/Giacobini-Zinner

摘要

We report on ground-based optical and space infrared observations of cornet 21P/Giacobini-Zinner. Our data indicate that the comet is quite active with fairly uniform coma emission out to r 3.8 AU, absent large numbers of jets or other coma features. Dust production measurements combined with no visibly detected extended coma emission suggest that comet activity turned off 3.8 AU post-perihelion. The color of the coma is slightly redder than the Sun, and no variations in the light curve of 21P were evident. The 24 micron Spitzer image shows a strong dust coma and tail, but no evidence for a dust trail, even though this cornet is the parent body of the Draconid meteor stream.