2 Observations

The photoelectric observational material discussed in this paper was obtained

in the interval between December 17, 1993 and December 1, 1994 at the Skalnaté Pleso (SP) and Stará Lesná (SL) Observatories of the Astronomical Institute of the Slovak Academy of Sciences (Cassegrain 600/7500 telescope equipped with the single-channel photometer/digital converter system), at the Hlohovec Observatory (H) (Cassegrain 600/7500, single-channel photometer/mechanical signal recording device) and at the Nicolaus Copernicus Observatory in Brno (B) (Nasmyth 400, single-channel photometer/digital converter). The moments of the individual observations, U, B and V magnitudes and colour indexes (U- B) and (B - V) are listed in Table 1. The accuracy of the photometric observations is expressed by the error which did not exceed the following values (in the individual colours): $U\pm 0.03$,$B \pm 0.02$ and $V\pm 0.02$, all in mags.

  

Figure 1: Photoelectric observations of V705 Cas in the V colour

  

Figure 2: Photoelectric observations of V705 Cas in the B colour

  

Table 1: Photoelectric observations of nova Cas 93

  

Figure 3: Visual observations of V705 Cas

  

Figure 4: The course of the development of the (U-B) index during the early decline of V705 Cas

The V colour light curve constructed from the data listed in Table 1, incorporating also data from Munari et al. (1994b) and from the VSNET network, is depicted in Fig. 1 and the B colour one in Fig. 2. Both light curves are fitted by the polynome of the fourth degree, in order to determine t_3,V and t_3,B parameters accurately. We have selected the degree of the polynome from among several possibilities tested on the basis of the accuracy of the fitting of the observational data. The reason for the incorporation of the visual brightness estimates communicated via the VSNET network was to achieve a more complete and detailed description of the photometric behaviour of the nova. The light curve based solely on these visual data is displayed in Fig. 3.