{
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Benjamin Schneider at MIT <bschn@mit.edu>",
  "eventId": "GRB 250610B",
  "bibcode": "2025GCN.40676....1S",
  "circularId": 40676,
  "editedOn": 1749652511868,
  "submittedHow": "web",
  "createdOn": 1749597997953,
  "body": "B. Schneider (LAM), A. de Ugarte Postigo (LAM), C. Adami (LAM/Pytheas/AMU), J.P Troncin (Pytheas/OHP), A. Martin-Carrillo (UCD), S. Basa (LAM/OHP/Pytheas/AMU), E. Le Floc'h (CEA/Irfu), K. Siellez (Institute of Astrophysics in Paris / UTas) report on behalf of a larger collaboration:\n\nWe observed the field of the GRB 250610B (Saccardi et al., GCN 40671) using the T120cm telescope at Observatoire de Haute-Provence (France). We obtained 30 minutes of exposure in the r-band starting at 20:31:03.29 UT on 2025-06-10 (3.97 hr after the trigger).\n\nIn the stacked image, we detected a new source not visible in the Legacy Survey and consistent with the XRT #1 error at RA, Dec 200.1796, +31.1047 which is equivalent to:\n\nRA(J2000) = 13:20:43.11\nDec(J2000) = +31:06:16.8\nwith an uncertainty of 0.5 arcsec.\n\nThe preliminary magnitude derived for that source is:\n\nr = 20.96 +/- 0.15 mag (AB)\n\nThe photometric calibration was performed using nearby stars from the SDSS catalog and the magnitude is not corrected for Galactic extinction.\n\nWe acknowledge the excellent support from Observatoire de Haute-Provence and in particular the students and professors from the summer camp OHP 2025.",
  "format": "text/plain",
  "submitter": "Benjamin Schneider at MIT <bschn@mit.edu>",
  "subject": "GRB 250610B: OHP/T120 optical counterpart candidate",
  "version": 2
}