\documentstyle[twoside,epsf]{article}

\input ibvs2.sty
\input ibvst.sty

\begin{document}

\IBVShead{4935}{5 August 2000}

\IBVStitle{BV Photometry of \boldmath{$\zeta$} A\lowercase{nd}}

\IBVSauth{Zhang Zhousheng; Li Yulan; Tan Huisong; Shan Hongguang}

\IBVSinsto{Yunnan Observatory, Academia Sinica, P.O. Box 110, Kunming, People's Republic of China\\ \indent e-mail: ynaowugj@public.km.yn.cn}


\SIMBADobjAlias{zeta And}{BD +23 106}

\begintext

\IBVSTnam{$\zeta$ And = BD\,+23\deg106}

\IBVSTcoo{0\hr44\mm41\sec}{+23\deg59\farcm7}{1950}

\IBVSTobs{Yunnan Observatory, Academia Sinica, 35-cm Cassegrain telescope}

\IBVSTdet{Unrefrigerated 1P21 photomultiplier}

\IBVSTfil{$BV$}

\IBVSTcomp{BD\,+22\deg153 = HD 5516}

\IBVSTchk{BD\,+23\deg126 = HD 5316}

\IBVSTsys{$UVB$}{Standard stars from Landolt (1983)}

\IBVSTdata{Electronically through IBVS Web-site as 4935-t1.txt}

\IBVSTtyp{ Ellipsoidal eclipsing binary }

\IBVSTrem{
The binary $\zeta$ And ($P=17.7693$ days) is of considerable interest, especially since 
Stebbins (1928) has found that there is a distortion wave amplitude of 0.02 
magnitude in the sinusoidal light variation of system. Photoelectric observations 
were obtained from October 1988 to February 1990, on 29 nights. The probable 
error of a single observation was estimated to be $\pm0.017$ magnitude. The phases 
were calculated with the light elements given by Danielkiewicz-Krosniak and 
Kurpinska-Winiarska (1991):$$
{\rm Hel.~Min.~I = J.D.}~2445253.180 + 17.7693\times E.
$$
The data are given in the Table~1 (4935-t1.txt, accessible only
electronically). The light curves are shown in Figure~1. It is worthy
to note that the light curves in 1990 have obviously changed their
shapes near 0.5 phase. Their minimum depths became shallower than
those in 1988-89.}

\IBVSfig{12cm}{4935-f1.ps}{The photoelectric $B$ and $V$ light curves of the $\zeta$ And in 1988-90, relative to BD\,+22\deg153}

\references

Danielkiewicz-Krosniak, E., Kurpinska-Winiarska, M., 1991, {\it Rocznik Astronomiczny
Obserwatorium Krakowskiego}, {\bf 63}, 3

Landolt, A. U., 1983, {\it Astron.\ J.}, {\bf 88}, 439

Stebbins, J., 1928, {\it Pub.\ Washburn Obs.}, {\bf 15}, 29


\IBVSedata{4935-t1.txt}

\end{document}

