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Alert Notice 151: Superoutburst of 0203+56A UV Persei AND Superoutburst of 0803+62 SU Ursae Majoris AND Supernova in NGC 4374 [SN 1991bg]

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AAVSO ALERT NOTICE 151 (December 24, 1991)


The cataclysmic variable 0203 + 56A UV Persei is undergoing a superoutburst, as
indicated by the following observations from AAVSO observers:

Dec  21.990 UT 12.3 G. Dyck, Assonet, MA
22.224  11.6 J. Griese, Rocky Hill, CT
23.032  11.0 C. Scovil, Stamford, CT
23.033  11.4 J. Griese
23.157  11.5 R. Stewart, W. Paterson, NJ
24.277  11.6 R. Stewart

Recent superoutbursts reported include May 1987 and October 1989, when UV Per
reached approximately 11.6. The most recent outburst was reported in January
1991, when the star reached approximately magnitude 12.0 and was bright for
approximately three days.

Please monitor UV Per closely, using the accompanying AAVSO chart, and report
your observations to AAVSO Headquarters.


This cataclysmic variable is also undergoing a superoutburst. Recent observations include

Dec  17.422 UT 12.2 R. Hays, Worth, IL
18.469  11.2 R. Hays
19.456  11.5 J. Bortle, Stormville, NY
19.47  11.5 G. Dyck, Assonet, MA
19.490  11.2 R. Hays
20.417  11.5 R. Royer, Lakewood, CA
23.000  11.9 G. Dyck
23.169  11.9 R. Stewart, W. Paterson, NJ

Please use the accompanying chart to observe SU UMa and report your observations to

SUPERNOVA IN NGC 4374  [SN 1991bg]

We have been informed by the Central Bureau for Astronomical Telegrams (IAU Circular 5400) of the report
by H. Kosai, National Astronomical Observatory of Japan, of the visual discovery of
a supernova in NGC 4374 (M84) by Reiki Kushida, YatSugatake South Base Observatory,
Japan, on December 9.844 UT. The supernova discovery was reported to the Bureau on
December 12. The position of the supernova (epoch 1950) is

   R.A 12h 22' 31.54"  Decl. +13deg 08' 52.4"

The presence of the supernova was confirmed by astronomers at the University of
California at Berkeley. It was confirmed spectroscopically as a Type Ia supernova,
although perhaps spectroscopically somewhat peculiar, by astronomers at the F.L.
Whipple Observatory, University of California at Berkeley, and Lawrence
Livermore National Laboratory.

A visual observation made on December 19.5 by C. Scovil indicated it had faded
to approximately magnitude 15, an estimate very difficult to make because of
the waxing moon and the very small observational window between moonset and
predawn. twilight. A photovisual observation made by R. Royer on December 20.5
indicated magnitude 14.2 for the supernova, although he commented that visually
the supernova could be fainter.

Observations of the supernova include

Nov  17.802 UT (15.1 photovisual, Y. Kushida, Yacsugatake South Base
     Observatory, Japan
Dec  3.77  14.9 photovisual, Y. Kushida
7.54  14.9: photovisual, R Royer, Lakewood, CA
9.844  14.0: visual, R Kushida, Yacsugatake South Base
     Observatory, Japan
9.860  14.5 photovisual, Y. Kushida
10.8  14.3: photoelectric V, T. Kato, National Astronomical
     Observatory, Japan
10.804  14.4 photovisual, Y. Kushida
19.5  15: visual, C. Scovil, Stamford, CT
20.5  14.2 photovisual, R Royer

Please use the enclosed chart of NGC 4374 to observe the supernova and report
your observations to Headquarters.

Our congratulations to Reiki on her visual discovery!

The answering machine (617-354-0484) will be on at Headquarters 24 hours a
day December 24 - 29, and will be checked twice daily. After December 29 it
will be on weekends and nights, as usual.

Janet Mattei, who is out of the country on a family matter, and I thank you
very much for your astronomical efforts and contributions. Best wishes to
you and your loved ones from us at AAVSO Headquarters for happy holidays.

Clear skies and good observing!

Elizabeth O. Waagen
Senior Technical Assistant


AAVSO UVPer f scale chart

AAVSO SU UMa e scale chart

NGC 4374 Thompson-Bryan chart - SN 1991bg

NGC 4374 chart - SN 1991bg



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