{
  "eventId": "GRB 250704A",
  "submittedHow": "web",
  "circularId": 40944,
  "format": "text/plain",
  "subject": "GRB 250704A: REM retraction of optical afterglow detection and updated limit",
  "submitter": "Riccardo Brivio at INAF-OAB <riccardo.brivio@inaf.it>",
  "body": "R. Brivio, M. Ferro (INAF-OAB), A. Rossi (INAF-OAS), P. D'Avanzo, S. Covino, D. Fugazza (INAF-OAB) report on behalf of the REM team:\n\nFurther analysis of the optical data obtained with REM (Brivio et al. GCN Circ. 40938) reveals that the source identified as the optical afterglow of GRB 250704A (Cao et al., GCN Circ. 40934) is spurious, likely resulting from a cosmic ray. From further analysis of the field, we obtain a 3sigma upper limit of:\nr > 18.1 (AB; calibrated against the Pan-STARRS catalogue),\nat a mid-time of 1.7 hr after the trigger.\n\nWe apologize for any confusion this may have caused.",
  "bibcode": "2025GCN.40944....1B",
  "createdOn": 1751626338739
}