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THE ASTRONOMER Electronic Circular No 1479      1999 Dec 16 21.38UT
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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SUPERNOVA 1999gl IN NGC 317B (=Q1999/303)
On 1999 Dec 14, Tom Boles reported a possible SN in NGC 317.
Research by the editor indicated this was a galaxy with two
components and that the suspect was close to NGC 317B.
Following independent optical confirmation by Mark Armstrong,
spectral results confirm it is a supernova of type-II. The IAUC
announcement follows:

G. M. Hurst, Basingstoke, England, reports the discovery by
Tom Boles, Wellingborough, of a supernova (mag 16.2) on unfiltered
CCD images obtained in the course of the U.K. Nova/Supernova Patrol
on Dec. 14.73 and 14.98 UT with a 0.36-m reflector.  Boles measured
the position of SN 1999gl to be R.A. = 0h57m40s.07, Decl. =
+43o47'35".6 (equinox 2000.0; mean of two exposures).  SN 1999gl
does not appear on an image obtained by Boles on Sept. 17.02
(limiting mag about 18).  M. Armstrong, Rolvenden, confirmed the
presence of SN 1999gl on Dec. 14.976 and notes that it was not
present on his own CCD image taken on Dec. 4.  The second Palomar
Sky Survey does not show anything at the position of SN 1999gl
(limiting mag about 20).  Boles found the supernova to be at mag
16.6 on Dec. 15.92.
     P. Garnavich, S. Jha, R. Kirshner, and P. Challis, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum of SN
1999gl was obtained by P. Berlind with the Fred L. Whipple
Observatory 1.5-m Tillinghast telescope on Dec. 16.1 UT, showing
the supernova to be a type-II event near maximum.  Broad H-alpha
and H-beta emissions, as well as He I 587.50nm, are evident in the
spectrum.  A deep Na I absorption line due to interstellar gas in
the host galaxy has an equivalent width of 0.3 nm, implying that
the supernova is heavily extinguished by dust.  Strong, narrow
emission lines from the host galaxy provide a redshift of 0.018.
IAUC 7333

Guy M Hurst