Flare duration vs. flare energy using the raw integrated flare area and the fitted flare duration values. Left: τ flare duration values for flares in the Kepler 30 min sample as a function of flare energy on a log-log scale with linear fits to the values of individual stars. Only stars with ten flares at least are included. Right: slopes of the fitted lines from the left panel as a function of log g. Error bars show the uncertainties of the slopes, and the point sizes represent the number of flares observed on each star. The blue line shows a linear fit.