R-band light curves of GRB 060206 and GRB 060210

Both light curves show unusual behavior. GRB 060206 experienced a slow early decay, followed by a rapid increase in brightness by factor 2.5 about 1hr after the burst.

Its afterglow then faded in a broken power-law fashion, with a smooth break at t_b_=0.6 days, but with additional, less dramatic bumps and wiggles. The afterglow of GRB 060210 is also unusual: the light curve was more or less flat between 60 and 300s after the burst, followed by a 70% increase at 600s after the burst, after which the light curve declined as a ~t^-1.3^ power law. We argue that anomalous optical afterglows are likely to be the norm and that such rapid optical variations should be seen in many bursts, given good enough sampling.