Statistical analysis of the long-term visual light curve parameters of dwarf novae

The long-term visual light curve parameters of 36 dwarf novae are measured. The data is anayzed in search of likely relationships among the light curve parameters and system parameters. New relations of the orbital period with the mean light curve parameters are given. Our findings for the correlation analysis of individual systems agree with some of the results in previous studies. Almost all of the systems in this study have a bimodal frequency distribution of the outburst duration. By comparing the observational correlations with their theoretical counterparts, we find that the value of the viscosity parameter of the disk instability model is $\alpha_{\rm hot}\approx0.2$.