The optical rebrightening of GRB100814A: an interplay of forward and reverse shocks?

Understand

We present a wide dataset of gamma-ray, X-ray, UVOIR, and radio observations of the Swift GRB100814A.

• At the end of the slow decline phase of the X-ray and optical afterglow, this burst shows a sudden and prominent rebrightening in the optical band only, followed by a fast decay in both bands.
• The optical rebrightening also shows chromatic evolution.
• Such a puzzling behaviour cannot be explained by a single component model.