TITLE: GCN CIRCULAR NUMBER: 12804 SUBJECT: GRB111209A: ATCA detection at 5.5, 9, and 18GHz DATE: 12/01/04 05:37:27 GMT FROM: Paul Hancock at U of Sydney Paul J. Hancock, Tara Murphy, Bryan Gaensler (U of Sydney), Ashley Zauderer (Harvard) Following our 34GHz non-detection (GCN12664) we observed GRB 111209A (GCN12632) with the Australia Telescope Compact Array (ATCA) at 5.5, 9, and 18GHz on the 14th of December (T=+5.1days). The mean observing time was 11:12UT at 5.5 and 9GHz, and 11:47UT at 18GHz. We easily detect the GRB at each frequency as listed below: Freq Flux 5.5GHz 0.85+/-0.04mJy 9GHz 0.97+/-0.06mJy 18GHz 3.23+/-0.05mJy We thank the staff of the ATCA for their help in organising these observations.