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\IBVShead{4670}{16 February 1999}

\IBVStitletl{Photoelectric times of minima}{ of some eclipsing binary systems}

\IBVSauth{SEL\.{I}M O. SELAM, B\.{I}ROL G\"{U}ROL, ZEKER\.{I}YA M\"UYESSERO\u{G}LU}

\IBVSinsto{Ankara University Observatory, Faculty of Science, TR-06100,
Tando\u{g}an, Ankara-TURKEY \\
E-mail: selim@astro1.science.ankara.edu.tr}

\SIMBADobj{V 346 Aql, SS Ari, LS Del, YY Eri, RX Her, AK Her, SW Lac}
\SIMBADobj{UV Psc, AW UMa, W UMa, HW Vir}
\IBVStyp{ M }
\IBVSkey{times of minima}  
\IBVSabs{We presented 27 photoelectric minima of 11 eclipsing binaries.}
\IBVSabs{Most of the minima observations are part of the complete}
\IBVSabs{light curve coverages.} 

\begintext

We present 27 photoelectric minima observations of 11 eclipsing binary
systems which was observed during several seasons and most of them are
part of the complete light curve coverages. All observations were obtained
with the 30 cm Maksutov telescope at the Ankara University Observatory. 
Differential observations were secured by using an OPTEC SSP-5A photometer
head which contains a side on R-1414 Hamamatsu photomultiplier. The
filters used are in close accordance with the standard Johnson's UBV and
reductions of the observations have been performed in the usual way
(Hardie, 1962).

The moments of minima and their standard errors for each filter were
calculated by using the well known method of Kwee \& van Woerden (1956). 
Weighted average values of times of minima of the observed systems are
given in Table 1, together with their minimum types, filters and
observers. Weighted averages and their mean errors for the minima times in
different filters were calculated with the formula given in G\"{u}rol \&
Selam (1994).

This work was partially supported by T\"{U}B\.{I}TAK-BAYG under the
project no.\,1369 ``Photoelectric Photometry of some Interacting Binary
Stars''. 
         
\references
         
G\"{u}rol, B. \& Selam, S., 1994, {\it IBVS}, No.\,4109
         
Hardie, R., 1962, {\it Astr.\ Tech.: Stars and Stellar Systems}, Vol.\ II, Univ.\ of Chicago Press, Chicago

Kwee, K. K. \& van Woerden, H., 1956, {\it Bull.\ Astron.\ Inst.\ Neth.}, {\bf 12}, 327

\endreferences

\newpage

\begin{table}[h]
\caption{Times of minima of observed systems}
\begin{center}
\begin{tabular}{lccccc}
\hline
System & Min HJD  & Mean error & Min  & Filter & Observers\\
       & 2400000+ &            & type &        & (*)      \\
\hline 
V346 Aql & 51040.33918 & 0.00025 & I  & BV  & My\\
         & 51041.44680 & 0.00025 & I  & BV  & My\\
SS Ari   & 50393.43951 & 0.00096 & II & UBV & Gr\\
         & 50729.38661 & 0.00169 & I  & UBV & Sl\\
LS Del   & 50301.47825 & 0.00145 & II & BV  & My\\
         & 50731.34013 & 0.00172 & I  & BV  & Sl\\
         & 50758.27261 & 0.00091 & I  & BV  & Gr\\
YY Eri   & 50758.42113 & 0.00058 & I  & BV  & Gr\\
         & 50759.54675 & 0.00032 & II & BV  & Gr\\
RX Her   & 50259.38072 & 0.00078 & II & UBV & Gr\\ 
AK Her   & 50259.45353 & 0.00054 & I  & UBV & Sl\\
SW Lac   & 50647.37854 & 0.00032 & I  & UBV & My\\
         & 50649.30233 & 0.00057 & II & BV  & My\\
         & 50649.46731 & 0.00106 & II & UBV & My\\
UV Psc   & 50715.52658 & 0.00114 & II & BV  & Sl\\
         & 50731.45062 & 0.00042 & I  & BV  & Sl\\
W UMa    & 50505.53455 & 0.00042 & II & UBV & Gr\\
         & 50511.37119 & 0.00024 & I  & UBV & Sl\\
AW UMa   & 50476.40952 & 0.00141 & II & UBV & Sl\\
         & 50477.50777 & 0.00081 & I  & UBV & Gr\\
HW Vir   & 50155.39460 & 0.00005 & I  & BV  & Gr\\
         & 50155.51190 & 0.00007 & I  & BV  & Gr\\
         & 50491.43000 & 0.00006 & I  & BV  & Gr\\
         & 50491.48860 & 0.00009 & II & B   & Gr\\
         & 50491.54670 & 0.00005 & I  & BV  & Gr\\
         & 50511.50570 & 0.00004 & I  & BV  & Sl\\
         & 50511.56360 & 0.00021 & II & V   & Sl\\
\hline
\end{tabular}

(*) Observers:\\
\centerline {Gr: B. G\"{u}rol, My: Z. M\"{u}yessero\u{g}lu, Sl: S. O.
Selam}
\end{center}
\end{table}

\newpage
\IBVStitle{Errata}
\vskip 18pt

In IBVS No.\,4380 we were presented photoelectric minima times of
several eclipsing binary systems. We explore some mistakes in
References and Table 1 due to the typing errors. The corrections are
as follows:

\begin{itemize}
\item {\it page 1, References:} The IBVS number of the first reference
should read as \underline{4109} instead of 4027

\item {\it page 2, Table 1:} the 3rd moment of minimum of V1073 Cyg
should read as 477\underline{76}.3453 instead of 47767.3453

\item {\it page 4, Table 1:} the name of the star V456 Oph was missing
in the 1st column, 2nd row of the table. This row should read as

\smallskip
\centerline{\underline{V456 Oph}\quad 50269.3834\quad 0.0002\quad I\quad BV\quad My}\hfill
\smallskip

\item {\it page 4, Table 1:} the minimum time of TX UMa should read as
49804.4\underline{848} instead of 49804.4760

\end{itemize}

\vskip 12mm

\hfill\hbox{Z. M\"{u}yessero\u{g}lu, B. G\"{u}rol, S. O. Selam}

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