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\begin{document}
\IBVShead{4361}{5 August 1996}
\title{New Supernova 1983 on Moscow plates}
\begintext

A new supernova was found in the course of the search for variable stars using
the positive-negative method. Moscow collection plates
taken with the 40 cm astrograph in Crimea were used for this study.
The discovery was reported in IAU Circ. No\,6439, where the supernova was 
designated as SN\,1983ab.

The finding chart is given in Figure 1.
The parent galaxy is not included in the major catalogues of bright
galaxies (NGC, IC, UGC, MCG), but it has a Guide Star Catalogue
designation (GSC 2586.0540, non-stellar object, $\alpha$=16\fh 22\fmm 34\fss 5,
$\delta$=$+36\degr 45'20''$, J2000.0). Moreover, coordinates
of the galaxy's center and of the supernova were measured on our plates
relative
to GSC stars. The coordinates of the galaxy are in good agreement with
those in the GSC,
and the coordinates of the supernova are $\alpha=16\fh 22\fmm 34\fss0$,
$\delta=+36\degr 45'25''$ (J2000.0). So the distance from the center
of the galaxy to the supernova is $6''$W and $5''$N.

The supernova was seen and estimated on 24 plates. The results are
given in Table 1. A standard sequence near M13 (Arp and Johnson, 1955;
Forbes and Dawson, 1986) and a CCD standard (Field 2) from
Crampton et al. (1988) were used to obtain the magnitudes of the
comparison stars (Table 2). The light curve is shown in Figure 2.
Open circles are uncertain observations.
The maximum was reached on JD2445582 (September 4, 1983) and its brightness
was $16.35B$ with an error of about $\pm0.15$ mag.

It is not possible to classify the supernova with certainty. Our
observations are only near the maximum, and the author cannot say
anything about the light curve's shape on the descending branch
and about the rate of the brightness decrease.

Finally,  note that no object on Palomar prints was seen at the supernova
position. The author has looked through about 310 plates that include the
investigated region. No sign of this star was found except the announced
case.

The author is grateful to Dr. N.N. Samus and N.E. Kurochkin for their
attention to this investigation, and to N.N. Pavlyuk for discussion
of the results.


\medskip
\begin{center}
Table 1. Observations of the supernova
\vskip 1mm
\begin{tabular}{cccccc}
\hline
JD\,2445...& $B$& JD\,2445...& $B$& JD\,2445...& $B$\\
\hline
\\
563.373&  $<17.7$&    582.299&  16.32&    588.348&  16.71 \\
574.260&  17.07&    582.344&  16.29&    589.260&  16.66 \\
576.291&  16.81&    583.256&  16.55&    589.300&  16.58 \\
578.268&  16.71&    583.298&  16.42&    589.336&  16.76 \\
580.300&  16.60&    584.271&  16.66&    590.310&  16.74 \\
581.271&  16.39&    586.265&  16.76&    591.350&  16.71:\\
581.321&  16.50&    587.265&  16.60&    592.348&  16.86:\\
581.365&  16.47&    588.262&  16.55&    605.218&  $<17.7$\\
582.259&  16.34&    588.308&  16.63&           &        \\
\hline
\end{tabular}
\vfill \eject

\centerline{2}
\epsfysize=6cm
\centerline{\epsffile{4361-f1.ps}}
\centerline{Figure 1}
\epsfysize=6cm
\centerline{\epsffile{4361-f2.ps}}
\centerline{Figure 2}
\vskip 5mm
Table 2. Comparison Stars
\vskip 1mm
\begin{tabular}{cc}
\hline
Star & $B$ \\
\hline
\\
$a$&  16.34\\
$b$&  16.86\\
$c$&  17.1 \\
$d$&  17.7 \\
\hline
\end{tabular}
\end{center}

\vskip .6cm

\beginauthors
\authorsrightcol
S.V. ANTIPIN
Sternberg Astronomical Institute
13, Universitetskij Prosp.,
Moscow 119899, Russia
\endauthors
\vskip -4mm
\references

Arp, H.C. and Johnson, H.L., 1955, {\sl ApJ}, {\bf 122}, 171

Forbes, D. and Dawson, P.C., 1986, {\sl PASP}, {\bf 98}, 102

Crampton, D., Cowley, A.P., Schmidtke, P.C., Janson, T., and Durrell, P.,
1988, {\sl AJ}, {\bf 96}, 816

\end{document}
