Skip to main content
New GCN Circulars features for September 2023! See news and announcements

GCN Circular 34641

GRB 230818A: radio observation with the VLA
2023-09-08T13:08:24Z (14 days ago)
Stefano Giarratana at University of Bologna <>
Submitted By
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.

Looking for U.S. government information and services? Visit