1 Introduction

The novalike MV Lyr has been classified during the last years as a VY Scl type cataclysmic variable (Ritter 1990). The long-term photometric characteristics of the star were established photographically by Weber (1961); Romano & Rosino (1980); Andronov & Shugarov (1982); Wenzel & Fuhrmann (1983); Andronov et al. (1988); Kraicheva & Genkov (1992); Rosino et al. (1993). These investigations showed that MV Lyr brightness varies irregularly between high ($B \simeq 12.5$ mag) and low ($B \simeq 18$ mag) states. Photoelectric studies of MV Lyr in high state carried out by Borisov (1992) and Skillman et al. (1995) pointed at two modulations presented simultaneously, one with a mean period of $0{\hbox{$.\!\!^{\rm d}$}}1379$ and another with a mean period of $3{\hbox{$.\!\!^{\rm d}$}}8$. The existence of quasi-periodic oscillations (QPOs) with a period near 47 min has also been assumed. Walker (1966) suspected that MV Lyr is a single-lined spectroscopic binary. Schneider et al. (1981) found its orbital period to be $0{\hbox{$.\!\!^{\rm d}$}}1336 \pm 0.0017$. At maximum the light curves displayed large amplitude flickering with a peak-to-peak amplitude reaching 0.3-0.4 mag (Walker 1954; Robinson et al. 1981). MV Lyr is also soft (Mason et al. 1979) and hard (Cordova et al. 1981) X-ray source.

In this paper we present our photoelectric observations of MV Lyr carried out during 1992-1993. The data were tested for periodic modulations and the flickering properties were investigated. In Sect. 5 a possible mechanism for the generation of the obseved "50 min" QPOs is discussed.

  

Table 1: Observational series of MV Lyr