TITLE: GCN CIRCULAR NUMBER: 40944 SUBJECT: GRB 250704A: REM retraction of optical afterglow detection and updated limit DATE: 25/07/04 10:52:18 GMT FROM: Riccardo Brivio at INAF-OAB riccardo.brivio@inaf.it
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:
Further 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: r > 18.1 (AB; calibrated against the Pan-STARRS catalogue), at a mid-time of 1.7 hr after the trigger.
We apologize for any confusion this may have caused.
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