{
  "bibcode": "2020GCN.28238....1G",
  "body": "S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:\n\nAnalysis of AstroSat CZTI data showed the detection of a long GRB 200809B, which was also detected by Fermi GBM (GCN #28236) and Swift/BAT-GUANO (Tohuvavohu A. et al., GCN #28237).\n\nThe source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-08-09 15:41:26.500 UT. The measured peak count rate associated with the burst is 371 +/- 30 cts/s above the background in the combined data of four quadrants, with a total of 706 +/- 7 cts. The local mean background count rate was 537 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 5.44 +/- 0.01 s.\n\nIt was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-08-09 15:41:25.000 UT. The measured peak count rate is 583 +/- 48 cts/s above the background in the combined Veto data of four quadrants, with a total of 785 +/- 19 cts. The local mean background count rate was 1637 +/- 2 cts/s.  We measure a T90 of 5.72 +/- 0.45 s from the cumulative Veto light curve.\n\nCZTI 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.",
  "circularId": 28238,
  "createdOn": 1597001494000,
  "email": "soumya@iucaa",
  "subject": "GRB 200809B: AstroSat CZTI detection",
  "submitter": "Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>",
  "eventId": "GRB 200809B"
}