TITLE: GCN CIRCULAR NUMBER: 18548 SUBJECT: GRB 151027B: ATCA radio detection DATE: 15/11/01 07:01:04 GMT FROM: Jochen Greiner at MPI J. Greiner (MPE), M. Wieringa (CSIRO), P. Wiseman (MPE) report for a larger consortium: We observed the field of GRB 151027B (Swift trigger 661869; Ukwatta et al., GCN 18499) simultaneously at 5.5 and 9 GHz with the Australia Telescope Compact Array (ATCA), beginning at October 30.54 UT for 3.3 hrs. At a mean frequency of 9 GHz (with 2 GHz bandwidth) we detect a source at ~67+/-10 microJy at the position of the optical afterglow (Malesani et al., GCN 18501; Wiseman et al., GCN 18507). At the redshift of z=4.063 (Xu et al., GCN 18506) this is among the most luminous GRB radio afterglows. We are grateful to P. Edwards for scheduling this observation.