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Alert Notices

          THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
                25 Birch Street, Cambridge, MA 02138 USA
                       INTERNET:  aavso@aavso.org
                Tel. 617-354-0484       Fax 617-354-0665

                AAVSO ALERT NOTICE 266 (December 6, 1999)

0939-20 SUPERNOVA 1999gh IN NGC 2986

We have been informed by the Central Bureau for Astronomical Telegrams (IAU
Circular 7328 - http://cfa-www.harvard.edu/iau/cbat.html) that S. Nakano,
Sumoto, Japan, reports that Kesao Takamizawa, Saku-machi, Nagano-ken, Japan,
discovered a supernova in NGC 2986 on Dec. 3.806 UT at photovisual magnitude
14.6 on two 5-minute exposures on T-Max 400-120 film, using a 0.10-m f/4.0
lens.  Takamizawa reported that nothing was visible at the location of the
supernova down to magnitude 14.5-15.6 on 14 films taken by him between
January 1995 and November 26, 1998.

Nakano also reported that R. Kushida, Yatsugatake South Base Observatory
(YSBO), Japan, obtained a CCD image of the supernova on Dec. 5.819 UT with
a 0.40-m f/6.3 Schmidt-Cassegrain reflector that showed it at CCD magnitude
14.8.  Kushida reported that nothing was visible down to magnitude 18 on CCD
images taken by her between December 1996 and February 1999.

A precise position of SN 1999gh, which is 52" east and 15.8" north of the
center of the galaxy, was obtained by Y. Kushida, YSBO, from R. Kushida's CCD
image and reported by Nakano (IAU Circular 7328) as:

     R.A. = 09h 44m 19.75s   Decl.= -21 degrees 16' 25.0" (Equinox 2000.0)

CCD spectroscopic observations obtained by A. Filippenko, University of
California at Berkeley, and P. Garnavich, Harvard-Smithsonian Center for
Astrophysics, on Dec. 5 UT using the Keck-II telescope showed that the
supernova is Type Ia, near maximum brightness (IAU Circular 7328).

Accompanying is a chart prepared by K. Malatesta, AAVSO Headquarters, using
an image from the Digitized Sky Survey and comparison star magnitudes
from the USNO A2.0 Catalogue; an AAVSO preliminary chart will be issued
tomorrow and posted on the AAVSO web and ftp sites.  Until the AAVSO chart
is available, please use the accompanying chart to observe 0939-20 SN 1999GH
and report your observations to AAVSO Headquarters so we may inform the
astronomical community.  Once the AAVSO chart is available, please use it to
make your observations.  Please be sure to indicate which chart and comparison
stars you used to make your estimates.

Congratulations to Kesao Takamizawa on his discovery!

1058+45 AN URSAE MAJORIS TO BE OBSERVED WITH EUVE SATELLITE

Colleagues at Lawrence Livermore National Laboratory have informed us that
they will be observing the AM Her-type xray magnetic variable AN UMa, currently
in its "down", faint state, with the EUVE satellite.  They have requested our
assistance in obtaining good optical coverage of this star over the coming
months.

Please observe AN UMa and report your observations to AAVSO Headquarters.
AAVSO "d" and "e" scale standard charts for AN UMa are available on the AAVSO
web and ftp sites.  If you need paper copies of these charts, please let us
know.

CHARTS AVAILABLE ON AAVSO WEB AND FTP SITES

Electronic copies of the SN 1999gh and AN UMa charts mentioned in this Alert
Notice are available through our web site at the following address:

                         http://www.aavso.org

The charts may also be obtained directly from our FTP site:

       ftp.aavso.org (198.116.78.5), in /alerts/alert266   and
                                       /CHARTS/STANDARD/UMA )

The answering machine at AAVSO Headquarters is on nights and weekends for
your convenience. Please call our charge-free number (888-802-STAR =
888-802-7827) to report your observations. We also encourage observers to
send observations by fax to 617-354-0665 or by e-mail through the Internet
to observations@aavso.org.

Many thanks for your valuable astronomical contributions and your efforts.

Good observing!

Janet A. Mattei
Director

Elizabeth O. Waagen
Senior Technical Assistant


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AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484