TITLE: GCN CIRCULAR NUMBER: 45340 SUBJECT: GRB 260809A: NOT optical observations DATE: 26/08/10 08:11:19 GMT FROM: Andrea Saccardi at CEA/Irfu <andrea.saccardi@cea.fr> L. Izzo (INAF/OACN and DARK/NBI), A. Saccardi (CEA/Irfu), G. Corcoran (UCD), report on behalf of a larger collaboration: We observed the field of GRB 260809A detected by SVOM/ECLAIRs (Brunet et al., GCN 45331), using the ALFOSC camera mounted on the Nordic Optical Telescope (NOT). We obtained 3x300 s exposures in the SDSS r-band and 5x200s in the SDSS z-band. In the stacked images, we detect the optical afterglow (Li et al., GCN 45336; Adami et al., GCN 45338; Rajabov et al., GCN 45339). We measure the following magnitudes calibrated against the Pan-STARRS catalog, and not corrected for Galactic extinction: r = 23.78+/-0.18, midtime: 2026-08-10 at 04:29:51 UT (13.54 hr post trigger) z = 22.25+/-0.13, midtime: 2026-08-10 at 04:47:47 UT (13.84 hr post trigger). View this GCN Circular online at https://gcn.nasa.gov/circulars/45340. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...