TITLE: GCN CIRCULAR NUMBER: 32433 SUBJECT: GRB 220729A: AstroSat CZTI detection DATE: 22/07/31 06:02:37 GMT FROM: Varun Bhalerao at Indian Inst of Tech R. Gopalakrishnan (IUCAA), V. Prasad (IUCAA), G. Waratkar (IITB), A. Suresh (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 short GRB 220729A which was also detected by Fermi GBM (TrigNum: 680782656). The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2022-07-29 10:17:31.550 UTC. The measured peak count rate associated with the burst is 556 (+159, -157) counts/s above the background in the combined data of all quadrants, with a total of 145 (+54, -58) counts. The local mean background count rate was 455 (+9, -12) counts/s. Using cumulative rates, we measure a T90 of 0.63 (+0.22, -0.42) s. 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.