New peculiarities of cometary outburst activity

On the basis of long-time investigations of light curves, outburst activity and photometric evolution of comets the following new peculiarities of cometary outburst activity had been found: 1. For all observed comets brightness outbursts are occurring on the same heliocentric distances; 2. A quasi-periodicity of cometary outburst activity had been found. A mean value of this period is T = 6.8d (+/-) 0.6d; 3. The moments of sudden changes of the values of potometric parameter n coincide with the brightness outbursts of comets.; 4. During brightness outbursts of comets the values of O-C (the deviations of observational photometric center from the mass center of cometary nucleus) are increasing. These phenomena, found by authors, are new observational criterions for the development of a mechanism of cometary outburst activity.