TITLE: GCN CIRCULAR NUMBER: 20235 SUBJECT: GRB 161202A: Astrosat CZTI detection DATE: 16/12/05 07:58:12 GMT FROM: Vidushi Sharma at IUCAA V. Sharma, V. Bhalerao and D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed clear detection of a long duration GRB161202A (Swift detection: B. Sbarufatti et al., GCN Circ. 20227) in the 40-200 keV energy range. The light curve shows a multiple peak structure with main peak at 23:11:50 UT, 62 secs before the Swift BAT trigger(consistent with GCN 20233). The measured peak count rate is 230.75 counts/sec above the background in combined data of four quadrants, with a total of 1432.98 counts. The local mean background count rate was 345.25 counts/sec. Using cumulative rates, we measure a T90 of 75.25 sec. 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, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.