The optical (red) and radio (blue) light curves of PTF11agg.  The rapidly fading optical emission, together with the long-lived radio flux, indicates the presence of at least mildly relativistic ejecta.  However, no high-energy counterpart (i.e., GRB) was discovered.  As such, it is one of the best candidates for an "orphan" afterglow to date.  From \cite{Cenko2013}.