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\IBVShead{4375}{24 September 1996}

\title{PHOTOELECTRIC $BVR_c$ OBSERVATIONS AND NEW ELEMENTS OF}
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\title{THE CEPHEID HD\,32456}

\begintext
Recently Bastian et al. (1996) and Campos-Cucarella et al. (1996)
published light curves in $B$ and $V$ filters and light elements,
based on a short time span, for the bright Cepheid HD\,32456 found
by Makarov et al. (1994).

To refine the  published ephemeris, we have analysed photographic archival plates
at Sternberg Astronomical Institute of Moscow (80 estimates)
and at Astronomical Institute of Tashkent (28 estimates). We also
observed HD\,32456 photoelectrically at Mt. Maidanak
observatory  in August 1996, where
the 60-cm reflector was used and 17 $BVR_c$
measurements were obtained (Table 1); the accuracy
of the individual data is near 0.01 mag in all filters.
According to our data, the amplitude of the light
curve (Figure 1) is  0\fm 59 in $V$, 0\fm 27  in $B-V$ and 0\fm 13 in ${V-R}_c$.
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\centerline{Figure 1}
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Table 1
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\begin{tabular}{cccccccccc}
\hline
JD hel&Phase&$V$&$B-V$&${V-R}_c$&JD hel&Phase&V&$B-V$&${V-R}_c$\\
2450000+ & & & & &2450000+ & & & & \\
\hline
\\
312.3420& .084&  7.304& 0.890&  .572& 319.3408& .208&  7.458& 0.974&  .612\\
314.3428& .691&  7.814& 1.102&  .664& 320.3198& .505&  7.738& 1.087&  .665\\
314.4746& .731&  7.795& 1.081&  .653& 321.3042& .804&  7.699& 1.011&  .628\\
315.3352& .992&  7.227& 0.833&  .537& 322.3015& .107&  7.328& 0.909&  .573\\
315.4506& .027&  7.241& 0.852&  .549& 322.4339& .147&  7.390& 0.935&  .595\\
316.4355& .326&  7.593& 1.041&  .643& 323.3132& .414&  7.688& 1.037&  .677\\
317.4789& .643&  7.801& 1.102&  .670& 324.3567& .731&  7.791& 1.072&  .652\\
318.3112& .896&  7.372& 0.888&  .557& 325.3814& .042&  7.243& 0.869&  .552\\
318.4680& .943&  7.245& 0.833&  .543&         &     &       &      &      \\
\hline
\end{tabular}
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\centerline{2}
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\centerline{Figure 2}
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Table 2
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\begin{tabular}{cccrrc}
\hline
Max JD hel & Error & Filter & E & $O-C$ & Number \\
2400000+ & & & & & of observations \\
\hline
\\
16567.2012&  0.0766& PG&$-$5122&   $-$0.0637&    12\\
17522.7952&  0.0667& PG&$-$4832&    0.0537&    13\\
28260.2223&  0.0654& PG&$-$1573&   $-$0.0997&    23\\
36839.7696&  0.0780& PG& 1031&   $-$0.0736&    14\\
36839.8578&  0.0899& PV& 1031&    0.0146&    14\\
48216.6518&  0.0681& PG& 4484&    0.0473&    32\\
50318.5951&  0.0029&  B& 5122&   $-$0.0580&    17\\
50318.6230&  0.0042&  V& 5122&   $-$0.0301&    17\\
\hline
\end{tabular}
\end{center}


All observations obtained were analysed  with Hertzsprung's method;
the derived epochs of maxima are given in Table 2.
These epochs of maxima, together with those published
by Bastian et al. (1996) and Campos-Cucarella et al. (1996),
were introduced into a linear least-squares solution
which resulted in the following improved ephemeris formula:
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\centerline{Max JD hel = 2433442.959 + 3.2947470 $\times$ E}
\hspace*{73mm}$\pm$.031\ \ \ \ \ \ \ \ \ \ \ $\pm$.72
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This ephemeris was used in calculating the phases in Table 1 and
the $O-C$ values in Table 2 as well as for
plotting our observations in Figure 1 and $O-C$ diagram in Figure~2,
where the above mentioned published epoches of maxima are marked by crosses.

The study described in this publication was made possible in part
by grants
No. 95--02--05276 and No. 94--02--04347 from the Russian
Foundation of Basic Research.

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\beginauthors
 L.N. BERDNIKOV
 O.V. VOZYAKOVA
 Sternberg Astronomical Institute
 13, Universitetskij prosp.
 Moscow 119899, Russia
\authorsrightcol
 V.V. IGNATOVA
 Astronomical Institute
 33, Astronomicheskaya ul.
 Tashkent 520000, Uzbekistan
\endauthors
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\references

Bastian, U., Born, E., Agerer, F., Dahm, M., Grossmann, V., Makarov, V., 1996, {\it IBVS}, No.\,4306

Campos-Cucarella, F., Guarro-Flo, J., Gomez-Forrelad, J.M., Garcia-Melendo, E., 1996, {\it IBVS}, No.\,4317

Makarov, V., Bastian, V., Hoeg, E., Grossmann, V., Wicenec, A., 1994, {\it IBVS}, No.\,4118



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