{
  "format": "text/plain",
  "createdOn": 1728415117325,
  "eventId": "GRB 241006A",
  "bibcode": "2024GCN.37738....1H",
  "body": "T. Hussenot-Desenonges (IJCLAB), Y. Rajabov (UBAI), M. Tanasan (NARIT), I. Abdi (AUS), R.Strausbaugh (EIU), S. Antier (OCA), S. Karpov (FZU), M. Coughlin (UMN), C. Andrade (UMN), I. Tosta e Melo (UniCT-DFA), P. Hello, N. Leroy (IJCLAB), P-A Duverne (APC), T. Pradier (Unistra/IPHC), N. Guessoum (AUS), L. De Almeida, W. Corradi, N. Sasaki, F. Navarete, L. Braga (LNA), K. Noysena (NARIT)\non behalf of the GRANDMA collaboration.\n\nWe performed observations with the GRANDMA network on the field of GRB 241006A, detected by Swift-BAT (GCN 37722).\nThe first images were taken at OPD starting from 2024-10-07T01:01:42, 3 hours after the GRB trigger, in the I and R filters. TRT-SBO also observed the field in R and I filters starting from 2024-10-07T09:26:52, 11.5 hours after the trigger.\n\nWe did not detect any optical counterparts of the Swift-XRT afterglow position (RaDec 304.74263 -40.80500, GCN 37724), with the following 5-sigma upperlimits at its coordinates:\n\n+-------------+-------------+--------+----------+-----------+-------------+\n| MJD (start) | T-T0 (days) | Filter | Exposure | Telescope | U.L. (Vega) |\n|-------------+-------------+--------+----------+-----------+-------------+\n| 60590.0429  | 0.1318      | I      | 16x360s  | OPD       | 19.6        |\n|-------------+-------------+--------+----------+-----------+-------------+\n| 60590.0556  | 0.1445      | R      | 9x360s   | OPD       | 20.1        |\n|-------------+-------------+--------+----------+-----------+-------------+\n| 60590.3937  | 0.4826      | R      | 5x300s   | TRT-SBO   | 21.6        |\n|-------------+-------------+--------+----------+-----------+-------------+\n| 60590.4079  | 0.4968      | I      | 5x300s   | TRT-SBO   | 20.0        |\n+-------------+-------------+--------+----------+-----------+-------------+\n\nWe also searched the Swift-BAT field (RA, Dec 304.794, -40.796, uncertainty 3 arcmin) and did not detect any optical counterpart. The 5-sigma upperlimits on the field are:\n+-------------+-------------+--------+----------+-----------+-------------+\n| MJD (start) | T-T0 (days) | Filter | Exposure | Telescope | U.L. (Vega) |\n|-------------+-------------+--------+----------+-----------+-------------+\n| 60590.0429  | 0.1318      | I      | 16x360s  | OPD       | 19.4        |\n|-------------+-------------+--------+----------+-----------+-------------+\n| 60590.0556  | 0.1445      | R      | 9x360s   | OPD       | 20.0        |\n|-------------+-------------+--------+----------+-----------+-------------+\n| 60590.3937  | 0.4826      | R      | 5x300s   | TRT-SBO   | 21.5        |\n|-------------+-------------+--------+----------+-----------+-------------+\n| 60590.4079  | 0.4968      | I      | 5x300s   | TRT-SBO   | 19.9        |\n+-------------+-------------+--------+----------+-----------+-------------+\n\n\n\nAll the data has been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022).\n\nWe use the SkyPortal application (skyportal.io) to monitor our observational campaign.\n\nGRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518)",
  "circularId": 37738,
  "submittedHow": "web",
  "subject": "GRB 241006A: GRANDMA optical upper limits",
  "submitter": "Thomas Hussenot-Desenonges at IJCLab <thomas.hussenot@ijclab.in2p3.fr>"
}