3 Period study

During the observations, five primary and four secondary times of minima were obtained and given in Table1. All available times of minima were collected from the literature. Together with the new times of minima from Table1, they were used in forming the (O-C) diagram (see Fig. 1). The light elements given by Landolt (1975) were used in estimating C values. The (O-C) diagram in Fig. 1 shows a parabolic variation indicating a continuous increase in period. The period increase is found to be $3.28\, \pm\, 0.26$ seconds per century. The corresponding quadratic light elements were obtained to be

$$\begin{eqnarray} &&\hspace*{-4mm}{\rm Hel\, Min\,I\, JD} \!=\! 24\,36814.7642 \... ...\, 18 \hspace{1.2cm} \pm 5 \hspace{0.8cm} \!\!\!\pm\, 8 \nonumber\end{eqnarray}$$ (1)

If the period increase is due to conservative mass transfer, then the mass transfer rate from the less massive to the more massive component should be about $5.0\, 10^{-6}$ solar mass per year. The phases of the light variation of the system were calculated with the following linear light elements:

$${\rm Hel\, Min\,I\, JD}=24\,36814.6751 + 1\hbox{$.\!\!^{\rm d}$}88553364\, {E},$$ (2)

which were obtained from the recent photoelectric times of minima.

  

Figure 1: The O-C diagram for V382 Cygni

  

Table 1: New times of minima of V382 Cygni