TITLE: GCN CIRCULAR NUMBER: 43504 SUBJECT: GRB 260120B: AstroSat CZTI detection DATE: 26/01/23 12:52:45 GMT FROM: Anuraag Arya at IIT Bombay <aryaanuraag910@gmail.com> A. Goyal (IITB), A. Arya (IITB), M. Tembhurnikar (IUCAA), S. Salunke (IUCAA), Harsha K. H. (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 GRB 260120B which was also detected by Swift BAT (M. Ferro et. ala, GCN Circ. 43479), Fermi GBM (Fermi GBM Team, GCN Circ. 43477), Swift XRT (Goad et al., GCN Circ. 43484), and SVOM/C-GFT (Wu et al., GCN Circ. 43483). The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2026-01-20 18:00:23.85 UTC. The measured peak count rate associated with the burst is 312 (+129, -23) counts/s above the background in the combined data of three quadrants (out of four), with a total of 622 (+153, -176) counts. The local mean background count rate was 174 (+4, -6) counts/s. Using cumulative rates, we measure a T90 of 5.0 (+1.5, -1.5) s. The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2026-01-20 18:00:22.68 UTC. The measured peak count rate associated with the burst is 333 (+65, -44) counts/s above the background in the combined data of all quadrants, with a total of 1026 (+266, -251) counts. The local mean background count rate was 1065 (+7, -9) counts/s. We measure a T90 of 4.3 (+1.6, -1.8) s from the cumulative Veto light curve. 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/43504. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...