TITLE: GCN CIRCULAR NUMBER: 40353 SUBJECT: GRB 250504A: VLT/X-shooter upper limits DATE: 25/05/05 19:26:55 GMT FROM: Andrea Saccardi at CEA/Irfu <andrea.saccardi@cea.fr> A. Saccardi (CEA/Irfu), M. Garnichey (LUX-Paris Obs.), D. B. Malesani (DAWN/NBI and Radboud), G. Corcoran (UCD), A. Martin-Carrillo (UCD), B. Schneider (LAM), N. R. Tanvir (Leicester), A. de Ugarte Postigo (LAM) report on behalf of the Stargate collaboration: We observed the field of GRB 250504A detected by Fermi/GBM (Fermi GBM team, GCN 40342; Bala et al., GCN 40346) and Swift/BAT (Moss et al., GCN 40343) using the ESO VLT UT3 (Melipal) with the X-shooter acquisition camera. A short sequence of imaging was secured in the r (3x30 s), g (3x60 s), and z (3x40 s) bands. No afterglow is detected consistent with the optical position reported by de Wet et al. (GCN 40347) with the following 5 sigma upper limit calibrated against nearby SkyMapper stars: r > 23.4 (AB) on 2025 May 05 at 03:21:58 UT (3.93 hr after the burst). We acknowledge excellent support from the ESO observing staff in Paranal, in particular Abigail Frost, Florian Rodler, Marco Berton, and Rodrigo Palominos. View this GCN Circular online at https://gcn.nasa.gov/circulars/40353. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...