The Frequency of Outbursts of the Dwarf Nova U Geminorum

U Geminorum visual data from 1855 through 1985 are used to determine variations in the frequency of outbursts of this dwarf nova. Patterns in the O-C curve of times of outbursts resemble other types of dwarf novae in that intervals of more or less frequent outbursts occur for periods of up to ten years. The duration of outbursts is determined to be bimodal with peaks at 9 and 16 days. Wide outbursts tend to be more common when the interval between outbursts is longer. Changes in the published counts of maxima were determined to be necessary to correct discontinuities in the O-C curve. A new table of outbursts is presented.