TITLE: GCN CIRCULAR NUMBER: 39086 SUBJECT: GRB 250128B: TNG optical upper limit DATE: 25/01/29 16:17:05 GMT FROM: Riccardo Brivio at INAF-OAB riccardo.brivio@inaf.it

A. Rossi (INAF-OAS), R. Brivio, M. Ferro, P. D’Avanzo, S. Covino, D. Fugazza (INAF-OAB), L. Di Fabrizio, G. Mainella (INAF-TNG) report on behalf of the CIBO collaboration:

We observed the field of the short GRB 250128B detected by Fermi and Swift (Fermi GBM team, GCN 39057; Evans et al., GCN 39058) with the Italian 3.6m TNG telescope equipped with the optical camera DOLORES. A series of images were obtained with the i-sdss filter on 2025-01-29 at a mid-time of about 13.5 hours after the burst.

No clear afterglow candidate is detected within the UVOT-enhanced XRT position (Evans et al., GCN 39069) down to a 3-sigma limiting magnitude of i ~ 25.3 (AB; calibrated against the Pan-STARRS catalogue).

View this GCN Circular online at https://gcn.nasa.gov/circulars/39086. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...