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\input ibvs2.sty

\begin{document}

\IBVShead{4807}{24 November 1999}

\IBVStitletl{Two New Eclipsing Binary Systems in Cepheus:}{ the W UM\lowercase{a} NSV 14312 and the Eccentric EA GSC 3992\_0847}
 
\IBVSauth{HENDEN, ARNE A.$^1$; GUARRO-FLO, JOAN$^2$; GARCIA-MELENDO, ENRIQUE$^3$}

\IBVSinst{USRA/USNO, P.O. Box 1149, Flagstaff, AZ 86002-1149, USA, e-mail: aah@nofs.navy.mil}

\IBVSinst{Grup d'Estudis Astronomics, Apartado 9481, 08080 Barcelona, Spain, e-mail: gea@astro.gea.cesca.es}

\IBVSinst{Esteve Duran Observatory, El Montanya-Seva, 08553 Seva, Spain, e-mail: duranobs@astro.gea.cesca.es}

\SIMBADobj{NSV 14312}
\SIMBADobj{GSC 3992-0847}
\IBVStyp{ W UMa }
\IBVStyp{ Eccentric EA }

\begintext

NSV 14312 (WR 30, GSC 3992\_0731) is one of the R$_{\rm C}$I$_{\rm C}$ suspected variables reported by Weber (1958), and listed in the NSV Catalogue (Kholopov, 1982) as a Cepheid with a photographic variation range between 11\fmm8 and 12\fmm6.

To study variability of this star, NSV 14312 was included in a collaborative observing program between the US Naval Observatory Flagstaff
Station, the Grup d'Estudis Astronomics, and Esteve Duran Observatory. The
suspected variable was monitored in the ${{} BVR_{\rm C}I_{\rm C}}$ bands with the 1.0-m Ritchey--Chretien telescope at the USNO Flagstaff Station, and in the $V$ band with the 0.4-m Schmidt--Cassegrain telescope at Piera Observatory.

\IBVSfig{7.5cm}{4807-f1.ps}{Field of NSV 14312. V1 = NSV 14312 and V2 = GSC 3992\_0847. North is up.}

\begin{table}
\begin{center}
{\normalsize Table 1}
\vskip2mm
\begin{tabular}{cccccc}
\hline
Star & GSC & $V$ & ${{} B-V}$ & ${{} V-R}$ & ${{} R-I}$ \\
\hline
A & 3992-0033 & 13.572${}\pm{}$0.017 & 1.452${}\pm{}$0.030 & 0.778${}\pm{}$0.022 & 0.712${}\pm{}$0.021 \\
B & 3992-0111 & 12.063${}\pm{}$0.013 & 0.763${}\pm{}$0.013 & 0.413${}\pm{}$0.018 & 0.373${}\pm{}$0.022 \\
C & 3992-0154 & 10.256${}\pm{}$0.036 & 0.346${}\pm{}$0.018 & 0.250${}\pm{}$0.021 & 0.290${}\pm{}$0.022 \\
D & 3992-0316 & 12.860${}\pm{}$0.015 & 0.677${}\pm{}$0.017 & 0.412${}\pm{}$0.022 & 0.422${}\pm{}$0.026 \\
E & 3992-0349 & 10.197${}\pm{}$0.041 & 0.641${}\pm{}$0.029 & 0.366${}\pm{}$0.037 & 0.373${}\pm{}$0.042 \\
F & 3992-0371 & 11.134${}\pm{}$0.024 & 0.420${}\pm{}$0.018 & 0.246${}\pm{}$0.062 & 0.219${}\pm{}$0.075 \\
G & 3992-0393 & 12.918${}\pm{}$0.017 & 1.261${}\pm{}$0.018 & 0.690${}\pm{}$0.016 & 0.683${}\pm{}$0.016 \\
H & 3992-0444 & 13.088${}\pm{}$0.010 & 1.533${}\pm{}$0.018 & 0.815${}\pm{}$0.019 & 0.708${}\pm{}$0.038 \\
I & 3992-0450 & 12.277${}\pm{}$0.013 & 0.511${}\pm{}$0.017 & 0.298${}\pm{}$0.018 & 0.322${}\pm{}$0.018 \\
J & 3992-0491 & 11.721${}\pm{}$0.010 & 0.596${}\pm{}$0.013 & 0.348${}\pm{}$0.020 & 0.381${}\pm{}$0.024 \\
K & 3992-0596 & 12.666${}\pm{}$0.016 & 1.418${}\pm{}$0.021 & 0.785${}\pm{}$0.020 & 0.731${}\pm{}$0.020 \\
L & 3992-0677 & 11.161${}\pm{}$0.015 & 0.238${}\pm{}$0.019 & 0.134${}\pm{}$0.020 & 0.168${}\pm{}$0.020 \\
M & 3992-0750 & 12.244${}\pm{}$0.015 & 1.356${}\pm{}$0.019 & 0.738${}\pm{}$0.018 & 0.685${}\pm{}$0.021 \\
N & 3992-0772 & 12.296${}\pm{}$0.013 & 1.131${}\pm{}$0.056 & 0.642${}\pm{}$0.015 & 0.614${}\pm{}$0.018 \\
O & 3992-0781 & 14.174${}\pm{}$0.023 & 0.679${}\pm{}$0.031 & 0.413${}\pm{}$0.033 & 0.417${}\pm{}$0.049 \\
P & 3992-0850 & 11.384${}\pm{}$0.017 & 1.088${}\pm{}$0.022 & 0.597${}\pm{}$0.020 & 0.573${}\pm{}$0.026 \\
Q & 3992-0882 & 10.556${}\pm{}$0.036 & 1.142${}\pm{}$0.031 & 0.617${}\pm{}$0.032 & 0.576${}\pm{}$0.039 \\
R & 3992-1035 & 12.909${}\pm{}$0.013 & 0.768${}\pm{}$0.018 & 0.438${}\pm{}$0.022 & 0.416${}\pm{}$0.032 \\
S & 3992-1419 & 13.253${}\pm{}$0.020 & 1.407${}\pm{}$0.027 & 0.753${}\pm{}$0.031 & 0.749${}\pm{}$0.033 \\
\hline
\end{tabular}
\end{center}
\end{table}

\vskip-11pt
Several stars in the field of NSV 14312 were placed in the standard system
by using Landolt (1992) standards. GSC 3992\_0548 and GSC 3992\_0491 were used as primary comparison and check stars respectively. The field of NSV 14312 is shown in Figure 1, whereas Table 1 lists the standard $V$ magnitudes and color indices of comparison stars near the variable.

Observations show that NSV 14312 is not a Cepheid but an EW eclipsing binary system with a period of about 19 hours. This object has an amplitude
variation of $0.34 \pm 0.01$ magnitudes at primary minimum and $0.31 \pm 0.01$ magnitudes at secondary minimum (Figure~2). Standardized photometry gives an average maximum $V$ magnitude of $11.603 \pm 0.005$ for this star, and also average color indices ${{} B-V}=+0.730\pm0.015$, ${{} V-R}=+0.440 \pm 0.009$, and ${{} R-I}=+0.425 \pm 0.015$. Observations spanned a 742 day period between October 1995 and November 1997, with the computed ephemeris:
$$ \begin{array}{r@{}r@{}l}
{\rm Min.~I = HJD~} 2450433.3516 & {} + 0.805074 & {} \times E. \\
                      \pm 0.0010 &  \pm 0.000004 \\
\end{array} $$

While monitoring the light changes of NSV 14312, the variability of GSC~3992\_0847 was discovered from CCD frames taken at the Piera Observatory. Photometric data indicates that this object is an EA eclipsing binary system with a period over 6.6 days. The variable fades $0.69 \pm 0.02$ magnitudes at primary minimum and $0.54 \pm 0.02$ magnitudes at secondary minimum. Observations also show that the components of this system follow eccentric orbits, since the secondary minimum is at phase 0.423 (Figure~3). The star has an average maximum $V$ magnitude of $12.80 \pm 0.02$, and average color indices ${{} B-V} = 0.482 \pm 0.011$, ${{} V-R} = 0.271 \pm 0.017$, and ${{} R-I} = 0.302 \pm 0.030$. The computed ephemeris for GSC~3992\_0847 is:
$$ \begin{array}{r@{}r@{}l}
{\rm Min.~I = HJD~} 2450421.4411 & {} + 6.61844 & {} \times E. \\
                      \pm 0.0010 &  \pm 0.00002 \\
\end{array} $$

We would like to thank Josep M. Gomez for his work in determining the period of GSC 3992\_0847 and computing its ephemeris.

\IBVSfig{7.5cm}{4807-f2.ps}{}

\IBVSfig{7.5cm}{4807-f3.ps}{}

\references

Landolt, A.U., 1992, {\it AJ}, {\bf 104}, 340

Kholopov, P. N. (ed.), 1982, New Catalogue of Suspected Variable Stars, Moscow

Weber, R., 1958, {\it JO}, {\bf 41}, 74

\vfill\eject


\IBVSerratum{4807}

The original title of IBVS 4807 contained an error:

``Two New Eclipsing Binary Systems in Cepheus: the W UM\lowercase{a}
NSV 14312 and the Eccentric EA GSC 3992\_30847''

The correct GSC number is, as used in the body of the paper: 3992\_0847 .

\bigskip

\hfill {\it The Editors}

\end{document}
