  The data collected by the Pierre Auger Observatory are analyzed to search for
coincidences between the arrival directions of high-energy cosmic rays and the
positions in the sky of astrophysical transients. Special attention is directed
towards gamma ray observations recorded by NASA's Swift mission, which have an
angular resolution similar to that of the Auger surface detectors. In
particular, we check our data for evidence of a signal associated with the
giant flare that came from the soft gamma repeater 1806-20 on December 27,
2004.
