TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2894 SUBJECT: GRB 041219: WSRT Radio Afterglow Detection DATE: 04/12/21 13:41:10 GMT FROM: Alexander van der Horst at U of Amsterdam A.J. van der Horst (University of Amsterdam), E. Rol (University of Leicester) and R. Strom (ASTRON, University of Amsterdam) report on behalf of a larger collaboration: "We observed the INTEGRAL GRB 041219 (GCN 2866) at 4.9 GHz with the Westerbork Synthesis Radio Telescope on December 20 from 15.55 to 23.59 UT, i.e. 1.59 - 1.93 days after the burst. We detect a radio source at the position of the infrared afterglow reported by Bloom et al. (GCN 2893) with an average flux density of 205 +/- 20 microJy, and a probable increase in the flux density during the observation. This measurement is in agreement with the radio detection at 8.5 GHz reported by Soderberg & Frail (GCN 2881). Further observations are planned." This message may be cited.