TITLE:   GCN CIRCULAR
NUMBER:  21205
SUBJECT: GRB 170529A: AstroSat CZTI detection
DATE:    17/06/05 17:42:58 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat data showed the CZTI detection of a long bright GRB 170529A, which was also detected by IPN triangulation(Hurley et al., GCN 21165) and Konus-wind(Kozlova A., GCN 21167).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks emission with the strongest peak at 07:05:48.567 UT, ~7 s after the Konus-wind Trigger. The measured peak count rate is 1508.5 cts/s above the background in combined data of four quadrants, with a total of 17280 cts. The local mean background count rate was 390.5 cts/s. Using cumulative rates, we measure a T90 of 33.5 s.

It was clearly detected in the CsI anticoincidence detector (Veto) also as in the 100-500 keV energy range.

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.