Distribution of brightenings of periodic comets during solar activity cycles 9-22

The paper provides another look at some questions related to long-standing problem of cometary physics - a relationship between cometary brightness and solar activity. For the 15 short-period comets with the largest number of returns, the positive deviations of their brightness in individual returns from the long-term trend were analyzed. The covered period from 1850 to 1987 corresponds to the cycles of solar activity from 9 to 22. Altogether, 59 brightenings in the range from 0.5m to 3.0m when compared to the long-term course were identified. It was found that neither the number of brightenings nor the size depend on the phase of a solar cycle. Observed multiple brightenings (different comets in the same period) are also unrelated to any phase of a solar cycle.