TITLE: GCN CIRCULAR NUMBER: 44202 SUBJECT: GRB 260403A: AstroSat CZTI detection DATE: 26/04/03 10:09:38 GMT FROM: Anuraag Arya at IIT Bombay <aryaanuraag910@gmail.com> A. Goyal (IITB), A. Arya (IITB), M. Tembhurnikar (IUCAA), Harsha K. H. (IUCAA), S. Salunke (IUCAA), G. Waratkar (Caltech/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 260403A which was also detected by Fermi GBM team (GCN Circ. 44195). The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2026-04-03 02:31:28.51 UTC. The measured peak count rate associated with the burst is 53 (+33, -2) counts/s above the background in the combined data of three quadrants (out of four), with a total of 604 (+338, -211) counts. The local mean background count rate was 221 (+2, -3) counts/s. Using cumulative rates, we measure a T90 of 34 (+4, -14) s. The source was also faintly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. 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/44202. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...