{
  "format": "text/plain",
  "submitter": "d.s.oneill@bham.ac.uk",
  "eventType": [
    "GRB"
  ],
  "eventId": "GRB 260818B",
  "submittedHow": "web",
  "editedBy": "Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of d.s.oneill@bham.ac.uk",
  "editedOn": 1787163089307,
  "version": 2,
  "subject": "GRB 260818B: NOT optical upper limits",
  "body": "D O’Neill (U. Birmingham), B. Schneider (LAM), G. Corcoran (UCD), D. B. Malesani (DAWN/NBI and Radboud), D. Xu (NAOC), A. L. Bouquin (NOT), A. Schenone Zanuzzi (NOT), report on behalf of a larger collaboration:\n\nWe observed the field of GRB 260818B detected by SVOM/ECLAIRs (Cordier et al., GCN  45398), using the ALFOSC camera mounted on the Nordic Optical Telescope (NOT). We obtained 4x200 s exposures in the SDSS r-band starting on 2026-08-19 at 03:43:55 UT (7.55 hr post trigger) and 5x200 s in the SDSS z-band starting on 2026-08-19 at 03:59:24 UT (7.80 hr post trigger). \n\nBecause of the size of the ALFOSC field of view, only 58% of the ECLAIRs error circle could is covered in our stacked images.\n\nIn the stacked images we identify no new source and obtain the following upper limits:\n\nr > 23.7 AB mag\nz > 22.6 AB mag\n\nMagnitudes are calibrated against nearby stars from the Pan-STARRS catalog, and not corrected for Galactic extinction.\n",
  "circularId": 45403,
  "createdOn": 1787156011028
}