{
  "bibcode": "2021GCN.30477....1L",
  "body": "T. Laskar (U. of Bath) and S. Bhandari (CSIRO) report on behalf of a larger\ncollaboration:\n\n\"Following the initial detection of the radio counterpart of GRB 210702A\n(Lien et al., GCN 30351) with the Australia Telescope Compact Array (ATCA)\non 2021 July 06, 3.50 days after the burst (Laskar et al., GCN 30424), we\nhave been monitoring this source with ATCA at 5.5, 9.0, 16.7, 21.2, and 34\nGHz. The 34 GHz radio counterpart was observed to fade, until observations\ntaken on 2021 July 13 indicated a non-detection with map rms ~ 60 uJy at a\nmid-time of 10.3 days after the burst.\n\nWe observed GRB 210702A with ATCA again at the above frequencies beginning\non 2021 July 21 07:00 UTC with the array in a hybrid (H168) configuration.\nPreliminary analysis reveals a strong (> 10 sigma) detection at 34 GHz with\na flux density of ~ 0.7 mJy at a mid-time of 18.5 days after the burst,\nimplying a significant rebrightening of the radio afterglow. Similar\nrebrightening is observed at 21.2 and 16.7 GHz.\n\nDetailed analysis is ongoing and further observations are planned. We thank\nthe CSIRO staff for approving and scheduling these observations.\n\nThe Australia Telescope Compact Array is part of the Australia Telescope\nNational Facility which is funded by the Australian Government for\noperation as a National Facility managed by CSIRO. We acknowledge the\nGomeroi people as the traditional owners of the Observatory site.\"",
  "circularId": 30477,
  "createdOn": 1626993740000,
  "email": "tanmoylaskar@gmail.com",
  "subject": "GRB 210702A: ATCA detection of radio rebrightening",
  "submitter": "Tanmoy Laskar at U of Bath  <tanmoylaskar@gmail.com>",
  "eventId": "GRB 210702A"
}