TITLE: GCN CIRCULAR NUMBER: 44158 SUBJECT: GRB 260330B: LCO optical upper limits DATE: 26/03/30 18:58:32 GMT FROM: SVOM_group <svomgroup@bao.ac.cn> D. Turpin (CEA/Irfu), A. Saccardi (CEA/Irfu), G. X. Lan (IRAP), S. Guillot (IRAP), report on behalf of the SVOM mission team: We observed the field of GRB 260330B detected by SVOM (Lan et al., GCN 44157) with the LCO 1m telescope at Siding Spring Observatory equipped with the Sinistro instrument. Our observation started on 2026-03-30 at 17:05:41 UT (about 2.76 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 > 20.4 AB (5-sigma, mid-time 2.85 hr after the trigger); z > 19.2 AB (5-sigma, mid-time 2.86 hr after the trigger). This project is funded by the SVOM collaboration. View this GCN Circular online at https://gcn.nasa.gov/circulars/44158. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...