{
  "circularId": 38966,
  "body": "S. Giarratana (INAF-OAB), M. Giroletti (INAF-IRA),\nG. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.),\nN. Omodei (Stanford Univ.), O. S. Salafia (INAF-OAB)\n\nAt 07:53:14 UT on 2024 Dec 22 (T_mid = 4.65 days post-burst)\nthe Karl G. Jansky VLA observed the field of GRB 241217A /\nEP241217B (Brunet et al., GCN 38594; Williams et al., GCN 38599;\nZhou et al., GCN 38606; Ravasio et al., GCN 38625) in three bands,\nwith central frequencies of 6, 10 and 15 GHz.\n\nThe standard 3C147 was used as bandpass and flux density\ncalibrator, while J0530-2503 was used as phase calibrator.\n\nFrom a preliminary analysis, an unresolved radio source\nis tentatively detected at a position (J2000):\n\nRA: 05:36:36.321 +- 0.003\nDec: -25:17:49.39 +- 0.04\n\nconsistent with the X-ray (Williams et al., GCN 38599), optical\n(Qiu et al., GCN 38600; Freeburn et al., GCN 38642), and radio\n(An et al., GCN 38750) position of the transient.\n\nThe preliminary analysis yields the following results:\n\n================================================================\nT_mid\tFreq\tPeak\tr.m.s.\tBeam\t\tPA\n[days]\t[GHz]\t[uJy/b]\t[uJy/b]\t[arcsec^2]\t[deg]\n================================================================\n4.65\t6\t32\t7\t0.77x0.28\t26\n4.65\t10\t36\t8\t0.51x0.18\t32\n4.65\t15\t38\t7\t0.30x0.11\t24\n================================================================\n\nNo source is detected with a >3sigma confidence at the\naforementioned position in previous radio surveys (NVSS,\nVLASS, RACS), all of which have r.m.s. noise levels above\n100 uJy/b.\n\nWe would like to thank the staff of the VLA for approving, executing,\nand processing the observations.\n\nThe National Radio Astronomy Observatory is a facility of the National\nScience Foundation operated under cooperative agreement by Associated\nUniversities, Inc.\n\nThese observations were carried out as part of project SF171028,\napproved in the framework of the Fermi - NRAO joint program agreement.\n",
  "subject": "GRB 241217A / EP241217B: radio detection with the VLA",
  "bibcode": "2025GCN.38966....1G",
  "createdOn": 1737106145289,
  "eventId": "GRB 241217A",
  "submittedHow": "email",
  "submitter": "Stefano Giarratana at INAF-OAB <s.giarratana@ira.inaf.it>"
}