2 New observations

New photoelectric observations of WZ Cep are obtained by using the telescope with the aperture of 0.6 m at Maydanak Observatory (Uzbekistan) during 1995. SAO 10752 ($V=9\hbox{$.\!\!^{\rm m}$}045$, $U-B=-0\hbox{$.\!\!^{\rm m}$}042$, $B-V=0\hbox{$.\!\!^{\rm m}$}458$ and $V-R=0\hbox{$.\!\!^{\rm m}$}422$) is chosen as a comparison star. 428 (U), 438 (B), 452 (V) and 436 (R) observations are obtained during 29 nights. The data are available on request from the authors. Some basic features of these light curves are presented in Table 1. Due to the large error in the photon registration with the small telescope aperture in the U passband the corresponding light curve is poorly defined. Therefore, we excluded the U passband measurements from further analysis.

  

Table 1: Basic points on the averaged light curve of WZ Cep obtained during 1995

The use of the ephemeris given in the GCVS shows that the secondary minimum of the light curve is deeper than the primary one. Doubting about this result, we reanalysed all published observations of the light curve's minima for WZ Cep. We established that Balazs (1937) had correctly found the epoch of the primary minimum. Later, in the ephemeris given by Detre (1940), the epochs of the primary and the secondary minima were switched. Hoffmann (1984) also noticed this error in the ephemeris by Detre. Since Hoffman's paper has not drawn much attention, the incorrect ephemeris by Detre were adopted in GCVS. Based on all available observations of the primary minimum our analysis give the corrected value for the ephemeris of WZ Cep:

$${\rm Min \ I = Hel. \ JD} \ 2449890.3552 + 0\hbox{$.\!\!^{\rm d}$}41744677 \ \times \ E$$

$$\hspace*{4cm} \pm 0.0014 \pm 0\hbox{$.\!\!^{\rm d}$}00000009 .$$