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\IBVShead{4327}{22 April 1996}

\centerline{\ft UBV PHOTOMETRY OF V511 Per}
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\begintext

V511 Per (DHK 9) is an Algol type system discovered by Kaiser et al. (1990). Very
little is known about the system. Photoelectric observations reveal a primary
minimum of $\approx$ 0\fm 4 and the secondary minimum is almost insignificant.

New observation of V511 Per were made on 30 nights during 1990/1991
observing season with the 30 cm Maksutov telescope of Ankara University
Observatory. Differential observations were secured by using an EMI 9789QB
photomultiplier. All observations were made with Johnson's UBV filters. The
comparison star was BD+39\degr 0782 and check stars were BD+40\degr0748 and
BD+40\degr0729. The standard deviations of the comparison minus check stars
measurements are $0\fm 11(U)$, $0\fm 035(B)$ and $0\fm 039(V)$. These values
were averaged over the all comparison minus check measurements.
The light and colour curves of V511 Per are plotted in Figure 1 by using the
ephemeris given by Kaiser et al. (1990), as

\begin{center}
\noindent Min.\,I = HJD\,2435988.336+3\fd 0452976 $\times$ E
\end{center}

One minimum time is obtained from our own observations by using Kwee and van Woerden's (1956) method:

\begin{center}
\noindent Min.\,I = HJD\, 2448169.5174$\pm$0.0024
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The observational data can be obtained from the authors.

Figure 1 shows that phasing and thus the light elements by Kaiser et al.
(1990) do not need any revision. The phases outside eclipse are not
well covered in Figure 1, and no appreciable proximity effect is visible. We
therefore attempted the solution of the B and V light curves by using a simple
spherical model assumption (see Kopal and Demircan 1978, and Demircan 1978).
The mean solution, as given in Table 1, indicates that the system is highly
interacting with relatively large fractional radii of the components, and thus
the proximity effects would not be negligible. We therefore think the system
deserves further photometric and spectroscopic study.

The observational data can be obtained from authors.

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\centerline{Table 1. Some orbital parameters of V511 Per}
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\begin{tabular}{lcccccc}
\hline
\hline
  & $r_{1}$ & $r_{2}$ & $L_{1}$ & $U_{1}$ & i(\degr) & $K^{2}$\\
  & (fractional) & (fractional) & (fractional) & & & (E-5)\\
\hline
 B & 0.375 & 0.240 & 0.97 & 0.24 & 81.6 & 6.5\\
 V & 0.389 & 0.235 & 0.93 & 0.25 & 80.9 & 9.0\\
 Av. & 0.382 & 0.238 & 0.95 & 0.25 & 81.25 & 7.75\\
\hline
\end{tabular}
\end{center}
\vfill \eject

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\centerline{\epsffile{4327-f1.ps}}
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Figure 1. The light and colour curves of V511 Per. Solid line represents
theoretical light curve
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We thank Prof. Dr. O. Demircan for his encouragement and guidance.
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\beginauthors
\authorsrightcol
SAC\.IT \"{O}ZDEM\.IR
MEHMET TANRIVER
Ankara University Observatory, 
Faculty of Science
06100 Tando\u{g}an, Ankara
Turkey
\endauthors

\references

Demircan, O., 1978, PhD. Thesis, The University of Manchester

Kaiser, D.H., Baldwin, M.E., and Williams, D.B., 1990, {\it IBVS}, No.\,3442

Kopal, Z., and Demircan, O., 1978, {\it Ap\&SpSci.}, {\bf 55}, 241

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

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