TITLE: GCN CIRCULAR NUMBER: 32791 SUBJECT: GRB 221009A: Medicina Radio Telescope observations DATE: 22/10/18 14:16:50 GMT FROM: Marco Marongiu at Ferrara U marco.marongiu@unife.it
M. Marongiu, E. Egron, A. Pellizzoni (INAF/OAC), S. Righini (INAF/IRA), C. Guidorzi (UniFe), and S. Mulas (UniCa), report:
We observed GRB 221009A (Dichiara et al. GCN 32632) with the Medicina Radio Telescope (www.radiotelescopes.inaf.it) through single-dish imaging in X-band (central frequency 8.2 GHz, bandwidth 0.3 GHz) in two time intervals: (1) 13:30-19:30 UTC on October 14, 2022 (4.97-5.22 days after the burst), and (2) 11:30-19:30 UTC on October 17, 2022 (7.89-8.22 days after the burst).
In our analysis, at 5.1 days (after the burst) we detected a faint radio emission at 8.2 GHz with a flux density of 26 +- 5 mJy at a position consistent with the optical position (Dichiara et al., GCN 32632) and the radio position (Laskar et al., GCN 32740, Laskar et al., GCN 32757).
We did not detect any significant signal with a 2-sigma upper limit of 20 mJy at 8.1 days.
We acknowledge the scheduler and the staff of the Medicina Radio Telescope for approving and executing these observations.