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\IBVShead{4380}{7 October 1996}

\title{Photoelectric Minima of Some Eclipsing Binaries}

\begintext

We present 127 minima observations of 25 eclipsing binaries, not yet published
anywhere. These stars were observed during several seasons and most of minima
observations are part of 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 EMI 9789QB photomultiplier
before 29 September 1991 (HJD 2448528.5) and an OPTEC SSP-5A photometer head
which contains a side on R-1414 Hamamatsu photomultiplier after that date.
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
using the method of Kwee \& van Woerden (1956). The algorithm of this method
was applied to the computer by M\"{u}yessero\u{g}lu and G\"{u}rol. Weighted
average values of times of minima of these system 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).

We give our special thanks to the observers for their helps during the
observations.
\vspace*{1.5cm}
\beginauthors
\authorsrightcol
Zekeriya M\"{U}YESSERO\u{G}LU
Birol G\"{U}ROL and
Selim O. SELAM
Ankara University Observatory
Faculty of Science
TR\,06100 Tando\u{g}an, Ankara, Turkey
\endauthors

\references

G\"{u}rol, B. \& Selam, S., 1994, {\it IBVS},  No.\,4027

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

\vfill \eject

\centerline{2}
\vskip 1mm


\centering
\centerline{Table 1: Times of minima of observed systems}
\vskip 1mm
\normalsize
\begin{tabular}{cccccc}
\hline
System & Min HJD & mean error & Min & Filter & Observers \\
 & 2400000+ &  & type \\
\hline  \\
     RT And  & 49972.3730 & 0.0002 & II & UBV & Sl \\
             & 49973.3144 & 0.0001 & I  & UBV & Gr \\
             & 50000.3592 & 0.0001 & I  & UBV & Sl \\
             & 50001.3001 & 0.0003 & II & BV  & Gr \\
     XZ And  & 50008.4732 & 0.0001 & I  & UBV & Gr \\
     SS Ari  & 48928.4421 & 0.0003 & I  & UBV & My \\
             & 49341.3288 & 0.0006 & I  & UBV & Al \\
             & 49342.3464 & 0.0008 & II & UBV & Sl \\
             & 49625.3171 & 0.0015 & II & BV  & My \\
             & 49625.5210 & 0.0001 & I  & BV  & My \\
     CK Boo  & 49500.3766 & 0.0010 & I  & UBV & Hk \\
             & 49502.3353 & 0.0008 & II & UBV & \"{O}d \\
             & 50248.3374 & 0.0010 & I  & UBV & My \\
             & 50260.4143 & 0.0015 & I  & UBV & Gr \\
     KR Cyg  & 50266.4764 & 0.0013 & I  & BV  & My \\
    V1073 Cyg& 47761.4060 & 0.0010 & II & UBV & Sl \\
             & 47763.3764 & 0.0008 & I  & UBV & Sl \\
             & 47767.3453 & 0.0009 & II & UBV & \"{O}r \\
             & 48106.3953 & 0.0015 & II & UBV & Kh \\
             & 48132.3293 & 0.0027 & II & UBV & Sl \\
             & 48145.2951 & 0.0010 & I  & UBV & \"{O}d \\
             & 48482.4272 & 0.0028 & I  & BV  & \"{O}d \\
             & 48484.3966 & 0.0036 & II & BV  & Sl \\
             & 48488.3169 & 0.0014 & II & BV  & Al \\
             & 48489.4935 & 0.0018 & I  & BV  & Dn \\
             & 48864.3487 & 0.0008 & I  & UBV & Dr \\
             & 48865.5247 & 0.0013 & II & UBV & \"{O}d \\
             & 49236.4492 & 0.0014 & II & UBV & Al \\
     RX Her  & 49588.4010 & 0.0001 & I  & UBV & Gr \\
             & 49532.3732 & 0.0001 & II & UBV & Gr \\
     TX Her  & 49930.4693 & 0.0005 & I  & BV  & Sl \\
     HS Her  & 49509.4548 & 0.0018 & I  & UBV & \"{O}d \\
             & 49523.3757 & 0.0028 & II & UBV & My \\
             & 49545.4726 & 0.0010 & I  & UBV & Sl \\
             & 49559.3891 & 0.0024 & II & UBV & Sl \\
             & 49961.3763 & 0.0011 & I  & BV  & Sl \\
     FG Hya  & 47530.5958 & 0.0007 & I  & BV  & Sl \\
             & 47532.5624 & 0.0010 & I  & UBV & \"{O}r \\
             & 47952.3476 & 0.0010 & II & BV  & \"{O}r \\
             & 47953.3374 & 0.0009 & II & UBV & Gr \\
             & 47968.2512 & 0.0005 & I  & UBV & \"{O}r \\
             & 48308.3705 & 0.0011 & II & BV  & My \\
             & 49007.4727 & 0.0008 & I  & UBV & Al \\
             & 49046.3152 & 0.0002 & II & UBV & My \\
\hline
\end{tabular}
\large
\vfill \eject

{3}
\vskip 1mm
\centering
\centerline{Table 1: Continued}
\vskip 1mm
\normalsize
\begin{tabular}{cccccc}
\hline
System & Min HJD & mean error & Min & Filter & Observers \\
 & 2400000+ &  & type \\
\hline  \\
     FG Hya  & 49387.4305 & 0.0011 & I  & BV  & My \\      
             & 49401.3518 & 0.0012 & II & BV  & My \\
             & 49772.2926 & 0.0010 & I  & BV  & My \\
             & 49772.4570 & 0.0023 & II & BV  & My \\
             & 49779.3410 & 0.0010 & II & BV  & My \\
     SW Lac  & 47766.5308 & 0.0008 & II & BV  & My \\
             & 47769.4210 & 0.0004 & II & BV  & \"{O}r \\
             & 47771.3440 & 0.0005 & II & BV  & Gr \\
             & 47771.5097 & 0.0004 & I  & BV  & Gr \\
             & 47775.3574 & 0.0005 & I  & BV  & Kh \\
             & 48158.2975 & 0.0006 & I  & BV  & My \\
             & 48158.4553 & 0.0003 & II & BV  & My \\
             & 48159.4169 & 0.0005 & II & BV  & My \\
             & 48504.3532 & 0.0005 & I  & BV  & Gr \\
             & 48504.5116 & 0.0003 & II & BV  & Gr \\
             & 48505.3102 & 0.0005 & I  & BV  & My \\
             & 48505.4746 & 0.0004 & II & V   & My \\
             & 48537.3889 & 0.0002 & I  & BV  & \"{O}d \\
             & 48887.2921 & 0.0003 & I  & UBV & \"{O}d \\
             & 48887.4511 & 0.0003 & II & UBV & \"{O}d \\
             & 49242.3249 & 0.0003 & I  & UBV & \"{O}r \\
             & 49242.4838 & 0.0003 & II & UBV & \"{O}r \\
             & 49975.3209 & 0.0005 & II & UBV & My \\
             & 49975.4803 & 0.0003 & I  & UBV & My \\
             & 50010.2777 & 0.0001 & II & BV  & My \\
     UV Leo  & 47538.6165 & 0.0006 & I  & BV  & My \\
             & 47557.5204 & 0.0002 & II & UBV & My \\
             & 47559.6206 & 0.0004 & I  & UBV & My \\
             & 48277.6275 & 0.0002 & II & BV  & \"{O}r \\
             & 48308.5314 & 0.0001 & I  & BV  & \"{O}d \\
             & 48339.4340 & 0.0002 & II & BV  & \"{O}r \\
             & 49099.4448 & 0.0001 & I  & BV  & \"{O}d \\
             & 49103.3475 & 0.0001 & II & UBV & Gr \\
     XY Leo  & 47969.3225 & 0.0007 & II & BV  & \"{O}r \\
             & 47969.4655 & 0.0003 & I  & BV  & \"{O}r \\
             & 47970.3185 & 0.0006 & I  & BV  & My \\
             & 47970.4587 & 0.0004 & II & BV  & My \\
             & 49063.4202 & 0.0008 & II & UBV & Al \\
             & 49069.3865 & 0.0006 & II & UBV & Sl \\
             & 49101.3497 & 0.0006 & I  & UBV & Ak \\
             & 49360.6000 & 0.0004 & II & BV  & Dn \\
             & 49432.3373 & 0.0004 & I  & UBV & Al \\
             & 49446.4022 & 0.0004 & II & BV  & My \\
\hline
\end{tabular}
\large
\vfill \eject

\centerline{4}
\vskip 1mm
\centering
\centerline{Table 1: Continued}
\vskip 1mm
\normalsize
\begin{tabular}{cccccc}
\hline
System & Min HJD & mean error & Min & Filter & Observers \\
 & 2400000+ &  & type \\
\hline  \\
    V451 Oph & 49560.3397 & 0.0004 & II & UBV & Gr \\
             & 50269.3834 & 0.0002 & I  & BV  & My \\
             & 50274.4634 & 0.0001 & I  & UBV & Gr \\
             & 49539.3775 & 0.0001 & II & BV  & Gr \\
             & 49546.4921 & 0.0002 & II & BV  & Gr \\
             & 49567.3290 & 0.0001 & I  & UBV & Gr \\
     BB Peg  & 49243.4462 & 0.0011 & II:& UBV & \"{O}d \\
             & 49244.3490 & 0.0013 & I  & UBV & My \\
             & 49273.2689 & 0.0008 & I  & UBV & Gr \\
             & 49275.2600 & 0.0010 & II & UBV & Sl \\
     DI Peg  & 48935.3002 & 0.0008 & II & BV  & \"{O}d \\
             & 48939.2161 & 0.0003 & I  & UBV & Sl \\
             & 49246.3631 & 0.0006 & II & BV  & Hk \\
             & 49248.4963 & 0.0005 & II & BV  & Ak \\
             & 49276.2546 & 0.0007 & II & V   & Dn \\
             & 49277.3259 & 0.0001 & I  & UBV & Ak \\
             & 49553.5085 & 0.0001 & I  & UBV & Gr \\
             & 50050.3564 & 0.0001 & I  & UBV & Gr \\
     RT Per  & 49634.4624 & 0.0003 & I  & BV  & Dr \\
             & 49739.3638 & 0.0006 & II & BV  & Yc \\
     IQ Per  & 48546.4067 & 0.0011 & I  & UBV & \"{O}d \\
             & 48926.5043 & 0.0006 & I  & UBV & Ak \\
             & 49023.2577 & 0.0010 & II & UBV & Sl \\
     AQ Psc  & 49283.3250 & 0.0010 & I  & UBV & Dn \\
             & 49326.3696 & 0.0011 & II & UBV & \"{O}d \\
             & 49327.3203 & 0.0015 & II & UBV & \"{O}d \\
    V505 Sgr & 48858.3253 & 0.0004 & I  & UBV & \"{O}d \\
      W UMa  & 49797.3908 & 0.0003 & I  & UBV & Sl \\
     TX UMa  & 49804.4760 & 0.0008 & I  & BV  & Sl \\
     AW UMa  & 48644.5117 & 0.0006 & I  & UBV & Dr \\
             & 48649.5555 & 0.0008 & II & UBV & Dr \\
             & 49029.4962 & 0.0014 & II & UBV & Al \\
             & 49074.4635 & 0.0011 & I  & UBV & Dn \\
             & 49105.3933 & 0.0008 & II & UBV & Al \\
             & 49411.4063 & 0.0008 & I  & BV  & Ak \\
             & 49412.2867 & 0.0007 & I  & BV  & Al \\
             & 49412.5015 & 0.0011 & II & BV  & Sl \\
     AW UMa  & 49432.4636 & 0.0009 & I  & UBV & Al \\
     HW Vir  & 50155.3946 & 0.0001 & I  & BV  & Gr \\
             & 50155.5119 & 0.0001 & I  & BV  & Gr \\
\hline
\end{tabular}
\large
\vskip 2mm
\centerline {Observers:} 
\vskip 1mm
\centerline {My: Z. M\"{u}yessero\u{g}lu, Sl: S. O. Selam, Gr: B.
G\"{u}rol,}

\centerline {Ak: A. Akal{\i}n, Dr: \.{I}. E. Derman, \"{O}r: F.F.
\"{O}zeren,}

\centerline {Dn: H. D\"{u}ndar, Kh: G. Kahraman, \"{O}d: S. \"{O}zdemir,}

\centerline {Al: B. Albayrak, Yc: K. Y\"{u}ce, Hk: H. Ak}


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