Credit & Copyright: C. Lisse, M. Mumma (NASA/GSFC),
K. Dennerl, J. Schmidt, and J. Englhauser (MPE)
Explanation:
The first X-rays ever detected from a
comet were discovered from
Comet Hyakutake with the
ROSAT
satellite on March 27th.
The
discovery is particularly surprising because there was little previous
indication that comets emit any significant X-radiation. As the
comet passed the Earth in
late March, repeated observations with ROSAT also showed that the X-ray
brightness changed over just a few hours. The crescent shape of the X-ray
emission is also enigmatic. One possible explanation is that X-rays
emitted from the Sun are absorbed by water in the comet's coma causing
fluorescence. Another possible explanation involves interaction with the
solar
wind - fast moving particles streaming away from the
Sun.
Information:
The
Scale of the Universe Debate in April 1996
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day