TITLE:   GCN CIRCULAR
NUMBER:  38750
SUBJECT: GRB 241217a/EP241217b: ATCA Radio Detection 
DATE:    25/01/01 07:04:32 GMT
FROM:    Tao An at SHAO, CAS <antao@shao.ac.cn>

Tao An, Yuanqi Liu (Shanghai Astronomical Observatory, China), Jinjun Geng, Xuefeng Wu (Purple Mountain Observatory, China) report on behalf of the EP radio follow-up team:


We report continued radio follow-up observations of GRB 241217A/EP241217b  (Marius et al. GCN 38594; Zhou et al. GCN 38606) with the Australia Telescope Compact Array (ATCA), following our initial observations (GCN 38649).

In our subsequent observation on December 24 (UT14:00-18:30), we detect significant radio emission (>6σ) at both 5.5 GHz and 9 GHz frequencies. After careful reanalysis of our first epoch data (December 20 UT13:00-18:00), we detect a 5σ radio source at 5.5 GHz, while the 9 GHz band shows no significant detection.

Further ATCA observations are scheduled to monitor the temporal and spectral evolution of this source.

We thank the CSIRO Space and Astronomy staff, in particular Jamie Stevens, for supporting these observations in a timely manner. We acknowledge the Gomeroi people as the traditional owners of the Observatory site. The Australia Telescope Compact Array is part of the Australia Telescope National Facility which is funded by the Australian Government for operation as a National Facility managed by CSIRO.