{
  "bibcode": "2021GCN.29342....1N",
  "body": "D. Nadella (NITK), G. Waratkar (IITB), A. Vibhute (IUCAA), S. Gupta\n(IUCAA), P. Sawant (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A.\nR. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat\nCZTI collaboration:\n\nAnalysis of AstroSat CZTI data with the CIFT framework (Sharma et al, 2020,\narxiv:2011.07067) showed detection of a bright long GRB 210116A, which was\nalso detected by AstroSat LAXPC (GCN #29340).\n\nThe source was clearly detected in the 20-200 keV energy range. The light\ncurve showed a single strong peak at 2021-01-16 05:53:37.500 UT, in all\nfour quadrants of CZTI. Quadrant D was noisy, and we exclude it from\nfurther analysis. The measured peak count rate associated with the burst is\n781 (+54, -60) cts/s above the background in the combined data of three\nquadrants (out of four), with a total of 3156 (+232, -222) cts. The local\nmean background count rate was 395 (+3, -3) cts/s. Using cumulative rates,\nwe measure a T90 of 9.5 (+4.1, -1.8) s.\n\nIt was also clearly detected in the CsI anticoincidence (Veto) detector in\nthe 100-500 keV energy range. The light curve showed a single strong peak\nof emission in all four quadrants, with the strongest peak consistent with\nthe above timing. The measured peak count rate is 3039 (+131, -62) cts/s\nabove the background in the combined Veto data of four quadrants, with a\ntotal of 13614 (+475, -578) cts. The local mean background count rate was\n1842 (+6, -6) cts/s. We measure a T90 of 8.8 (+1.7, -1.0) s from the\ncumulative Veto light curve.\n\nCZTI GRB detections are reported regularly on the payload site at\nhttp://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led\nconsortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and\nPRL. The Indian Space Research Organisation funded, managed and facilitated\nthe project.",
  "circularId": 29342,
  "createdOn": 1611285865000,
  "email": "gauravwaratkar24@gmail.com",
  "subject": "GRB 210116A: AstroSat CZTI detection",
  "submitter": "Gaurav Waratkar at IIT Bombay  <gauravwaratkar24@gmail.com>",
  "eventId": "GRB 210116A"
}