You are currently viewing the abstract.
View Full TextLog in to view the full text
AAAS login provides access to Science for AAAS members, and access to other journals in the Science family to users who have purchased individual subscriptions.
More options
Download and print this article for your personal scholarly, research, and educational use.
Buy a single issue of Science for just $15 USD.
Abstract
After the unexpected discovery of x-rays emitted from comet C/1996 B2 (Hyakutake) with the Röntgen X-ray Satellite (ROSAT) in March 1996, x-ray emissions from comets C/1990 K1 (Levy), C/1990 N1 (Tsuchiya-Kiuchi), 45P (Honda–Mrkos–Pajdušáková), and C/1991 A2 (Arai), optically 300 to 30,000 times fainter than Hyakutake, were discovered in archival ROSAT data. These findings establish comets as a class of x-ray sources and allow their properties to be studied over a wide optical brightness range. The results indicate that charge exchange between highly charged heavy ions in the solar wind and cometary neutrals is the dominant process for the x-ray emission. Comets may thus be used as probes for monitoring the heavy-ion content of the solar wind.
↵* To whom correspondence should be addressed. E-mail: kod{at}mpe-garching.mpg.de
