AUSTIN, Texas (MARCH 16) AP - A University of Texas astronomer has observed the
first ghostly light ''echoes'' from Supernova 1987A, an exploding star that
lighted the southern skies in February 1987, the university announced. 

Arlin Crotts made the observations at the Carnegie Institution of Washington's
Las Campanas observatory in Chile, the university announced Tuesday. 

Theories predict that when a supernova explodes, some light from the flash
would light up or reflect off dusty clouds of gas and show up as faint arcs of
light long after the peak brightness of the supernova. Until now, however, no
supernova has been close enough and bright enough to test this prediction, UT
spokesman Danny Ewald said. 

Crotts found two arcs of light corresponding to echoes from supernova 1987A.
The echoed light should be that which was emitted when the supernova was at its
brightest, some 80 days after the explosion was detected. 

Crotts said the discovery of the light echo from supernova 1987A was
confirmation of a basic prediction on how a supernova should behave. 

The echo is useful for mapping the clouds of gas and dust that surround the
supernova, much as terrain-mapping radar gives information on and contours, UT
said in a statement announcing the discovery. 

According to scientists, previously observed supernovae have been so far
distant from Earth that light echoes were undistinguishable from the source, 
and the later-arriving light was misinterpreted as slower decay of the
supernova.