\documentstyle[twoside,epsf]{article}
\input ibvs2.sty
\input ibvst.sty

\begin{document}

\IBVShead{4778}{13 October 1999}

\IBVStitletl{New Elements and Light Curve of CR Tauri}{ \rm (BAV Mitteilungen No.\ 123)}

\IBVSauth{Franz AGERER}

\IBVSinsto{Bundesdeutsche Arbeitsge\-mein\-schaft f\"{u}r Ver\"{a}nderliche Sterne e.V. (BAV), Munsterdamm 90, D--12169~Berlin, Germany}

\SIMBADobj{CR Tau}

\begintext

\IBVSTnam{CR~Tau = S3949~Tau}

\IBVSTobs{Private Observatory, 20-cm SCT}

\IBVSTdet{SBIG ST6 camera}

\IBVSTfil{None}

\IBVSTcomp{GSC 1862.1685}

\IBVSTchk{GSC 1862.1725}

\IBVSTsysn

\IBVSTrem{CR~Tau was discovered by Hoffmeister (1949a). 15 photographic minima were used to derive the first elements (Hoffmeister 1949b). These elements are listed in the GCVS\@. Recently we could observe photoelectrically ten new mi\-ni\-ma, which showed the GCVS-ephemeris to be a spurious one. The minimum times are calculated according to the Kwee--van Woerden method (1956). Using all available photoelectric minima, a weighted least squares fit led to the new ephemeris: 
\belowdisplayskip -12pt
$$\begin{array}{r@{}r@{}l} 
{\rm Min~I = HJD~} 2451195.4818 & {} + 0\fday 68270353 & {} \times E.\\
\pm 2 & \pm 15 \\
\end{array}$$
}

\IBVSTack{Data from the Lichtenknecker Database were used}

\begin{center}
\normalsize
Table 1: Observed times of minima for CR~Tau, epochs and residuals computed with respect to the linear ephemeris derived in this paper. \\ [2mm]
\begin{tabular}{r@{.}lcr@{.}lr@{.}lc|r@{.}lcr@{.}lr@{.}lc}
\hline
\multicolumn{2}{c}{JD hel.} & \lower5pt\hbox{Type$^*$} & \multicolumn{2}{c}{\lower5pt\hbox{Epoch}} & \multicolumn{2}{l}{\lower5pt\hbox{$O-C$}} & \lower5pt\hbox{Ref.} & \multicolumn{2}{c}{JD hel.} & \lower5pt\hbox{Type$^*$} & \multicolumn{2}{c}{\lower5pt\hbox{Epoch}} & \multicolumn{2}{l}{\lower5pt\hbox{$O-C$}} & \lower5pt\hbox{Ref.} \\[-5pt]
\multicolumn{2}{c}{2400000+} & & \multicolumn{2}{c}{} & \multicolumn{2}{l}{} & & \multicolumn{2}{c}{2400000+}\\
\hline
26004 & 38 & P & $ -36899$ & 0 & $ -0$ & 02 & [1] & 31449 & 65 & P & $ -28923$ & 0 & $ +0$ & 00 & [1] \\
26313 & 70 & P & $ -36446$ & 0 & $ +0$ & 03 & [1] & 49688 & 756 & E: & $ -2207$ & 0 & $ +0$ & 001 & [2] \\
26355 & 27 & P & $ -36385$ & 0 & $ -0$ & 04 & [1] & 49726 & 307 & E: & $ -2152$ & 0 & $ +0$ & 003 & [2] \\
26634 & 51 & P & $ -35976$ & 0 & $ -0$ & 03 & [1] & 49734 & 4942 & E & $ -2140$ & 0 & $ -0$ & 0020 & [2] \\
26662 & 48 & P & $ -35935$ & 0 & $ -0$ & 05 & [1] & 49756 & 3431 & E & $ -2108$ & 0 & $ +0$ & 0003 & [2] \\
26718 & 45 & P & $ -35853$ & 0 & $ -0$ & 06 & [1] & 50428 & 4626 & E & $ -1124$ & 5 & $ -0$ & 0018 & [2] \\
26987 & 51 & P & $ -35459$ & 0 & $ +0$ & 01 & [1] & 50464 & 3073 & E & $ -1071$ & 0 & $ +0$ & 0010 & [2] \\
27342 & 51 & P & $ -34939$ & 0 & $ +0$ & 01 & [1] & 50849 & 3518 & E & $ -507$ & 0 & $ +0$ & 0007 & [2] \\
27368 & 45 & P & $ -34901$ & 0 & $ +0$ & 00 & [1] & 50863 & 3450 & E & $ -487$ & 5 & $ -0$ & 0015 & [2] \\
27394 & 39 & P & $ -34863$ & 0 & $ +0$ & 00 & [1] & 50864 & 3710 & E & $ -485$ & 0 & $ +0$ & 0004 & [3] \\
27396 & 41 & P & $ -34860$ & 0 & $ -0$ & 03 & [1] & 50864 & 3711 & E & $ -485$ & 0 & $ +0$ & 0005 & [2] \\
27535 & 36 & P & $ -34657$ & 5 & $ -0$ & 01 & [1] & 51185 & 2412 & E & $ -15$ & 0 & $ -0$ & 0000 & [4] \\
27688 & 60 & P & $ -34432$ & 0 & $ -0$ & 03 & [1] & 51195 & 4821 & E & $ 0$ & 0 & $ +0$ & 0003 & [2] \\
31447 & 63 & P & $ -28926$ & 0 & $ +0$ & 03 & [1] \\
\hline
\end{tabular}

$^*$ P denotes photographic minima (weight 1) and E CCD observed minima (weight 10).\\ Those marked with `:' got reduced weight~(5).\\{}
[1]: Hoffmeister (1949b), [2]: Agerer: this paper, [3]: Diethelm (1998), [4]: Diethelm (1999)
\end{center}

\IBVSfig{7.5cm}{4778-f1.eps}{Differential light curve of CR Tau, drawn with the new ephemeris}

\references

Diethelm, R., 1998, {\it BBSAG Bulletin} {\bf 117}

Diethelm, R., 1999, {\it BBSAG Bulletin} {\bf 119}

Hoffmeister, C., 1949a, {\it Erg.\ AN} {\bf 12}, 1

Hoffmeister, C., 1949b, {\it VSS} {\bf 1}, H3, 157
%Original: Hoffmeister, C., 1949b, {\it VSS} {\bf 1}, 3

Kholopov, P.~N.~et al.~1985, {\it General Catalogue of Variable Stars,}
4th Edition, Nauka, Moscow

Kwee, K.~K., van Woerden, H., 1956, {\it Bull.~Astr.~Inst.~Netherlands} {\bf 12}, 327

\end{document}
