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THE ASTRONOMER Electronic Circular No 1366.     1998 Dec 19 21.40UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074
INTERNET: GUY@TAHQ.DEMON.CO.UK             GMH at AST.STAR.RL.AC.UK
WORLD WIDE WEB                    http://www.demon.co.uk/astronomer
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COMET C/1995 O1 (HALE-BOPP)
Andrew Pearce, Nedlands, West Australia has observed this comet
today and immediately reported a nuclear outburst.

1998 Dec 19.78UT: m1=11.3, Dia=1.0', DC=9...0.41-m reflector
Extraordinary!  The comet has undergone some kind of nuclear
outburst as there is a very bright and condensed central
condensation.  The condensation contributes 90-95% of the total
light of the coma.  At first I thought that the comet was in front
of a bright field star which is not plotted on the GSC. However
after observing the comet for over an hour I was able to detect
motion in this 'field star'.  It has been necessary to estimate the
magnitude using the 'I' method.  At low power the coma is very
faint but can be traced for 0.5' away from the centre.  At higher
power it is almost non-existent! At 380x magnification, the
condensation still appears relatively stellar.  I have not seen
anything like this before!  Considering the comet is over 7 AU
from both the Sun and Earth, you have to wonder what could be
driving this outburst. It will be interesting to see if the
professionals have been following this.

Guy M Hurst