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              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 258 (May 3, 1999)

0915+51 SUPERNOVA 1999by IN NGC 2841

We have been informed by the Central Bureau for Astronomical Telegrams (IAU
Circular 7156) of the independent discovery by R. Arbour, South Wonston,
Hampshire, England, and by the Lick Observatory Supernova Search (LOSS) of an
apparent supernova in NGC 2841.  M. Papenkova, W. D. Li, and A. V. Filippenko,
University of California at Berkeley, report on behalf of the LOSS team that
the supernova was found on unfiltered CCD images obtained on April 30.2 and
May 1.2 UT at magnitude approximately 15.7 and 15.0, respectively, using the
0.8-m Katzman Automatic Imaging Telescope (KAIT).  Arbour reports that his
unfiltered CCD image obtained April 30.8749 using a 0.3-m f/6.3 Schmidt-
Cassegrain reflector showed the supernova at magnitude 15.1.

According to a position forwarded by Arbour (IAU Circular 7156) and
obtained by M. Armstrong, Rolvenden, England, on an image taken Apr.
30.904 UT, the supernova is located at

         R.A. = 09h 21m 52.07s     Dec. = +51 degrees 00' 06.6"   (2000).

A pre-discovery image obtained by Arbour on April 28.8786 UT showed the
supernova at CCD magnitude 16.0-16.5.  Patrol images taken by Arbour on
April 10, 14, 22, 23, and 27 showed no new object down to CCD magnitude
17.5. A KAIT image of the field taken April 25.2 UT showed nothing at the
position of the supernova down to CCD magnitude 19.3 (IAU Circular 7156). 

An additional observation was reported to the AAVSO on May 1 by Erno
Berko, Ludanyhalaszi, Hungary, who found the supernova to be magnitude
approximately 15.5 - 16 on an unfiltered CCD image he obtained on April
30.837 UT using a 4-inch f/6 APO-refractor. 

Accompanying is a chart of NGC 2841 revised from the Thompson and Bryan
Supernova Search Charts and Handbook (Cambridge University Press, 1989)
and showing the location of the supernova.  The sequence given here is
the photometric one given by B. Skiff, Lowell Observatory, in vsnet-alert
2917;  the magnitudes are virtually the same as in the Corwin and Frueh
sequence on the published Thompson and Bryan chart, but Skiff's
magnitudes are given here because they go to two decimal places and so
are more appropriate for CCD observations.  As always, the magnitudes on
the chart are written with the decimal point omitted to avoid confusion
with stellar images; for example, magnitude 13.51 is written 1351. 

Please use the accompanying chart and sequence to observe 0915+51 SN
1999by and report your observations to AAVSO, being sure to indicate
which comparison stars you used to make your observations of this bright
supernova. 

Congratulations to Ron and to the Lick Observatory Supernova Search team on
their discoveries!

CHARTS AVAILABLE ON AAVSO WEB AND FTP SITES

Electronic copies of the revised Thompson/Bryan chart mentioned in this Alert
Notice are available through our web site at the following address:

                            http://www.aavso.org

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

               ftp.aavso.org (198.116.78.5), in /alerts/alert258)


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

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