\documentstyle[epsf]{article}
\input ibvs.sty

\begin{document}
\IBVShead{4427}{20 January 1997}

\centerline{\ft NSV\,00821, A NEW OVERCONTACT ECLIPSING BINARY SYSTEM}
\centerline{\ft  IN TRIANGULUM}


\vskip 10mm
\begintext

NSV\,00821 (= Wr\,139 = CSV\,005986 = GSC\,2327.1518) was announced as a possible
Cepheid by Weber (1963) with a photographic magnitude variation from 11\fm 8
to 12\fm 5 without giving any further information. To check it, the star was
included in the program of the Grup d'Estudis Astronomics for observing
poorly studied variables. An initial monitoring with the 0.4-m telescope at
Mollet del Valles Observatory showed that NSV\,00821 is not a Cepheid but
an overcontact eclipsing binary system. It was then decided to follow this 
object with the 0.5-m telescope at L'Ametlla del Valles Observatory (Spain).
NSV\,00821 was observed for 21 nights between 27 September and 26 December
1996. GSC\,2327.1604 and GSC\,2327.1636 were used as comparison and check stars
respectively. The Guide Star Catalog records GSC\,2327.1518 (NSV\,00821) with a
photovisual magnitude of 11.48 $\pm$ 0.40 (PAL--V1 filter).
\vskip 5mm

\epsfysize=11cm
\centerline{\epsffile{4427-f1.ps}}
\vskip 5mm
\centerline{Figure 1}

\vfill \eject

\centerline{2}
\vskip 1mm
Observations obtained in the V band with a CCD camera, confirmed our
preliminary data in the sense that NSV\,00821 is an overcontact eclipsing
binary system, with a period close to 16 hours 50 minutes (Figure 1). The 
amplitude of the light variation is 0.41 $\pm$0.01 magnitude at minimum I, which is a 
transit, and 0.39 $\pm$0.01 magnitude at minimum II, which is an occultation. The 
following ephemeris has been computed:
\vskip 5mm
 \hspace*{3cm}Min.\,I = HJD\,2450416.41635 + 0\fd 70170 $\times$ E
 
 \hspace*{6.3cm} $\pm$0.00047    $\pm$\ \,0.00002

\vskip 1.5cm
\beginauthors
\authorsrightcol
 J.M. GOMEZ-FORRELLAD
 A. GARRIGOS SANCHEZ
 Grup d'Estudis Astronomics
 Apartado 9481
 08080 Barcelona
 Spain
 e-mail: jmgomez@astro.gea.cesca.es
\endauthors

\vskip 8mm
Reference:

Weber, R., 1963, {\it IBVS},  No.\,21

\end{document}
