TITLE: GCN CIRCULAR NUMBER: 45466 SUBJECT: GRB 260825A: AstroSat CZTI detection DATE: 26/08/29 08:02:52 GMT FROM: Anuraag Arya at IIT Bombay <aryaanuraag910@gmail.com> Harsha K. H. (IUCAA), S. Salunke(IUCAA), A. Arya (IITB), A. Goyal (IITB), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long duration GRB 260825A which was also detected by Fermi (Fermi GBM team, GCN Circ. 45439). The source was clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2026-08-25 13:07:14.95 UTC. The measured peak count rate associated with the burst is 161 (+58, -1) counts/s above the background in the combined data of all quadrants, with a total of 7311 (+1106, -1122) counts. The local mean background count rate was 660 (+2, -2) counts/s. We measure a T90 of 206 (+23, -17) s from the cumulative Veto light curve. The duration of T90 is long due to a small flare at 2026-08-25 13:09:11.95 UTC. If this is not related to the burst, the primary has T90 of 63 (+6, -26) s. CZTI data products like interactive and downloadable light curves for this GRB can be found at: https://astrosat.iucaa.in/cift/cift_products/525359231.45/S525359231.45_deta... CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project. CZTI GRB detections are reported regularly on the payload site at: http://astrosat.iucaa.in/czti/?q=grb View this GCN Circular online at https://gcn.nasa.gov/circulars/45466. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...