GCN Circular 11211
A. de Ugarte Postigo (DARK/NBI), S. Martin Ruiz (ESO), G. Petitpas (SMA), and A. J. Castro-Tirado (IAA-CSIC) report on behalf of a larger collaboration: "We have observed the field of GRB 100901A (Immler et al. GCNC 11159) from SMA in the 345 GHz band starting on September 3rd at 9 UT (43.5 h after the burst). The observing conditions were very good, with a water vapour of PWV~1 mm. However, preliminary analysis does not show any new source at the position of the afterglow down to a 3-sigma limit of 2.25 mJy."