TITLE: GCN CIRCULAR NUMBER: 32364 SUBJECT: GRB 220707A: AstroSat CZTI detection DATE: 22/07/11 15:34:31 GMT FROM: Gaurav Waratkar at IIT,Bombay A. Suresh (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 GRB 220707A. It was also reported by INTEGRAL (Notice 9976,0). The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2022-07-07 20:37:31.0 UTC. The measured peak count rate associated with the burst is 73 (+10 -9) counts/s above the background in the combined data of three quadrants, with a total of 3687 (+409 -429) counts. The local mean background count rate was 332 (+1 -1) counts/s. Using cumulative rates, we measure a T90 of 75 (+11 -11) s. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2022-07-07 20:37:29.6 UTC. The measured peak count rate is 380 (+82 -10) counts/s above the background in the combined Veto data of all quadrants, with a total of 15340 (+1048 -1023) counts. The local mean background count rate was 1343 (+3 -4) counts/s. We measure a T90 of 81 (+7 -6) s from the cumulative Veto light curve. CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. 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.