\documentstyle[twoside,epsf]{article}

\input ibvs2.sty
\input ibvst.sty

\begin{document}

\IBVShead{4923}{20 July 2000}

\IBVStitle{BD\,+62\deg2167: a New Eclipsing Binary in the Field of CW C\lowercase{ep}}

\IBVSauth{Gomez-Forrellad, J.M.}

\IBVSinsto{Grup d'Estudis Astronomics, Apartado 9481, 08080 Barcelona, Spain}

\IBVSinsto{Esteve Duran Observatory Foundation, Montseny 46 -- Urb.\ El Montanya,
08553 Seva, Barcelona, Spain, e-mail:jmgomez@astrogea.org}

\SIMBADobj{BD +62 2167}

\begintext

\IBVSTnam{BD\,+62\deg2167 = GSC 4282\_394}

\IBVSTcoo{23\hr 05\mm 15\sec}{+63\deg 23\arcm 42\arcs}{2000.0}

\IBVSTobs{Mollet Observatory, 0.41-m Newtonian telescope}

\IBVSTdet{CCD}

\IBVSTfil{$V$}

\IBVSTcomp{SAO 20406 = BD\,+62\deg2166}

\IBVSTchk{GSC 4282\_778}

\IBVSTsysn

\IBVSTdata{Upon request}

\IBVSTtyp{ EA }

\IBVSfig{9cm}{4923-f1.eps}

\IBVSfig{11cm}{4923-f2.eps}

\IBVSTrem{
In a photometric program for searching for new variables with an 8-cm
automatic telescope at Mollet Observatory, it was found that GSC
4282\_394 of 9\fmm4 (Figure 1) is an Algol type eclipsing binary star
with a period of 1\fday3 and an amplitude of 0\fmm21 in $V$. The star
is a visual double and both components are listed as suspected
variables in the Tycho Catalogue (1997) with the `W' flag: TYC
4282\_394\_1 with a variation range between 9.11 and 9.75 ($B-V =
0.427$), and TYC 4281\_394\_2 (identified with BD\,+62\deg2167) with a
brightness range from 9.49 to 10.25 ($B-V = 0.394$). This flag
indicates that data suggest variability, although other instrumental
effects cannot be ruled out, as directly quoted from the Tycho
Catalogue's notes: ``variability suspected in the Tycho data; this may
due to intrinsic variability since no correlation with position angle
was evident. But no thorough investigation has been carried out to
eliminate other reasons intrinsic to the Tycho measurements.'' Since
the separation between the stars is about 6 arcseconds, joint
photometry of both stars was performed.\\
The light curve suggests that the EA system is also intrinsically
variable at some phases (Figure 2), probably due to activity in the
system.  These irregularities have an amplitude of 0\fmm03, and are
more important on the light-curve maxima and are permanently present in
the phase intervals 0.2--0.4 and 0.8--0.9, i.e., before the beginning
of both eclipses, and also during the secondary minimum affecting its
shape and depth. The amplitude of minimum II was variable between 0\fmm154
and 0\fmm180. Since it is unlikely that independent intrinsic
variations of the optical companion could match the eclipsing binary in
such a selective way, real intrinsic light changes for the eclipsing
binary system are highly probable.\\
Observations did not allow to determine which of the visual components
of GSC 4282\_394 is the Algol-type variable, and it was not possible to
deduce it from the Tycho observations either, which do not show the
detected variability but a high scatter and spurious oscillations.\\
The following ephemeris was computed:
$$\begin{array}{r@{}r@{}l}
{\rm Min.~I = HJD}~2451034.5344 & {} + 1.3045 & {} \times E. \\
{} \pm 0.0004 & {} \pm 0.0003 \\
\end{array}$$
Also these minima timings were obtained:
\begin{center}
\begin{tabular}{l}
HJD $2451032.5768\pm0.0011$ (II)\\
HJD $2451036.4918\pm0.0005$ (II)\\
HJD $2451038.4474\pm0.0014$ (I)\\
HJD $2451072.3621\pm0.0006$ (I)\\
\end{tabular}
\end{center}
}

\reference

ESA, 1997, The Hipparcos and Tycho Catalogues, ESA SP-1200

\end{document}
