TITLE: GCN CIRCULAR NUMBER: 19942 SUBJECT: GRB160917A: AstroSat CZTI detection DATE: 16/09/27 03:14:26 GMT FROM: Varun Bhalerao at IUCAA V. Bhalerao (IUCAA), V. Kumar (IUCAA), D. Bhattacharya (IUCAA), A. R. Rao (TIFR), S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration: Analysis of Astrosat data showed the CZTI detection of GRB160917A (Swift BAT detection: S.Barthelmy et al., GCN Circ. 19926). The source was clearly detected in the 40-200 keV energy range. The light curve shows a single peak at 11:30:25.0 UT, 6 seconds after Swift Trigger at 11:30:19.0 UT. The peak count rate was 116.0 counts/sec above the background (four quadrants summed together), with a total of 1008.0 counts. The local mean background count rate was 327.0 counts/sec. Using cumulative rates, we measure a T90 of 21 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.