TITLE: GCN CIRCULAR NUMBER: 45482 SUBJECT: GRB 260831B: LCO optical upper limits DATE: 26/09/01 06:56:51 GMT FROM: SVOM_group <svomgroup@bao.ac.cn> Y.X. Guan (GXU), A. Saccardi, D. Turpin (CEA/Irfu), C. Wu, L.P. Xin (NAOC), C.Guepin (LUPM), C. Plasse (HKU) report on behalf of the SVOM mission team: We observed the field of GRB 260831B (SVOM burst-id sb26083106 detected by SVOM (Godet et al., GCN 45477) with the LCO 1m telescope at Tenerife equipped with the Sinistro instrument. Our observation started on 2026-09-01 at 01:31:26 UT (about 6.92 hr after the trigger) and we obtained 3x200 s exposures in the SDSS r and 3x200 s exposures in the Pan-STARRS z filters. In the stacked image, we do not detect any new source within the SVOM/ECLAIRs error box. We measure the following upper limit calibrated against the Pan-STARRS DR1 catalog, and not corrected for Galactic extinction: r > 21.5 AB (5-sigma, mid-time 7.22 hr after the trigger); z > 20.2 AB (5-sigma, mid-time 7.01 hr after the trigger). This project is funded by the SVOM collaboration. View this GCN Circular online at https://gcn.nasa.gov/circulars/45482. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...