TITLE: GCN CIRCULAR NUMBER: 44645 SUBJECT: GRB 260515A: LCO optical counterpart detection DATE: 26/05/16 14:16:15 GMT FROM: Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf@iac.es> I. Pérez-Fournon (IAC and ULL), F. Poidevin (IAC and ULL), D. Cano-Morales, A.E. Hernández-Díaz, I. Correa-Plasencia, E. Lekaroz-Urriza, M. Quintana-Ansaldo (all ULL), A. López-Oramas (IAC and ULL), and D. Aguado (IAC and ULL) Following the detection of the SVOM/ECLAIRs GRB 260515A (Brunet et al., GCN 44622), detected also in Einstein Probe FXT follow-up observations (Wang et al., GCN 44642), we observed the field with one of the three Las Cumbres Observatory (LCO) 1-m telescopes, equipped with Sinistro cameras, located at the LCO node at Sutherland Observatory, South Africa. The observation, a single exposure of 180 sec in the SDSS r' filter, started on 2026-05-15 at 21:17:54 UT, 2.16 hours after the SVOM trigger. The optical counterpart (He et al., GCN 44623; Saccardi et al., GCN 44624; Sosnovskij et al., GCN 44625; He et al., GCN 44626; Wu et al., GCN 44628; Malesani et al., GCN 44629; Dennefeld et al., GCN 44633; Li et al., GCN 44634; and Antier et al., GCN 44643) with redshift of z = 0.764 (Malesani et al., GCN 44629) is clearly detected in our image with an AB magnitude of r' = 20.32 +/- 0.10, calibrated against the PanSTARRS-1 DR2 catalog and not corrected for Galactic extinction. This work makes use of observations from the Las Cumbres Observatory global telescope network (LCO program IAC2026A-011, SGLF and Superluminous Supernovae surveys). This work made use of the Astro-COLIBRI platform (P. Reichherzer et al. 2021, ApJS, 256, 5). View this GCN Circular online at https://gcn.nasa.gov/circulars/44645. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...