TITLE: GCN CIRCULAR NUMBER: 34641 SUBJECT: GRB 230818A: radio observation with the VLA DATE: 23/09/08 13:08:24 GMT FROM: Stefano Giarratana at University of Bologna S. Giarratana (University of Bologna, INAF-IRA), M. Giroletti (INAF-IRA), G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.), N. Omodei (Stanford Univ.) At 23:33:30 UT on 2023 August 23 (T_mid = 5.02 days post-burst) the Karl G. Jansky VLA observed the field of GRB 230818A (Fermi GBM team, GCN 34478; Tohuvavohu et al., GCN 34479) at a central frequency of 6 and 10 GHz. The standard J1331+3030 was used as bandpass and flux density calibrator, while J1912+3740 was used as phase calibrator. From a preliminary analysis, we do not detect the radio counterpart of GRB 230818A. The r.m.s. noise level of the images is 11 uJy/beam and 13 uJy/beam at 6 and 10 GHz, respectively. The synthesized beams are 0.44 x 0.89 arcsec (PA: 81 deg) at 6 GHz and 0.28 x 0.24 arcsec (PA: -70 deg) at 10 GHz. We would like to thank the staff of the VLA for approving, executing, and processing the observations. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. These observations were carried out as part of project SF161095, approved in the framework of the Fermi - NRAO joint program agreement.