TITLE: GCN CIRCULAR NUMBER: 20114 SUBJECT: GRB161023A: AstroSat CZTI detection DATE: 16/10/25 07:05:27 GMT FROM: Varun Bhalerao at IUCAA V. Sharma, V. Kumar, D. Bhattacharya and V. Bhalerao (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 GRB161023A (INTEGRAL detection: Sandro Mereghetti et al., GCN Circ. 20103) in the 40-200 keV energy range. The light curve shows a single peak at 22:39:10.00 UT, 30 seconds after the INTREGAL trigger at 22:38:40 UT. The measured peak count rate is 132.10 counts/sec above the background in combined data of four quadrants, with a total of 2846 counts. The local mean background count rate was 367.10 counts/sec. Using cumulative rates, we measure a T90 of 44 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.