{
  "bibcode": "2021GCN.29761....1L",
  "body": "S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC),\nH. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC),\nC. B. Markwardt (GSFC), K. L. Page (U Leicester),\nD. M. Palmer (LANL), T. Sakamoto (AGU),\nM. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):\n\nUsing the data set from T-60 to T+243 sec from the recent telemetry\ndownlink,\nwe report further analysis of BAT GRB 210402A (trigger #1040123)\n(Page et al., GCN Circ. 29743).  The BAT ground-calculated position is\nRA, Dec = 198.265, 44.510 deg which is\n   RA(J2000)  =  13h 13m 03.7s\n   Dec(J2000) = +44d 30' 36.1\"\nwith an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 69%.\n\nThe mask-weighted light curve shows a multi-peaked structure that\nstarts at ~T-50 s and ends at ~T+310 s. The main peak occurs\nat ~T+174 s. T90 (15-350 keV) is 238.7 +- 18.8 sec\n(estimated error including systematics).\n\nThe time-averaged spectrum from T-51.60 to T+310.20 sec is best fit by a\npower law\nwith an exponential cutoff.  This fit gives a photon index 1.49 +- 0.27,\nand Epeak of 63.6 +- 22.9 keV (chi squared 58.82 for 56 d.o.f.).  For this\nmodel the total fluence in the 15-150 keV band is 8.6 +- 0.4 x 10^-6 erg/cm2\nand the 1-sec peak flux measured from T+173.53 sec in the 15-150 keV band is\n1.6 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index\nof 1.87 +- 0.06 (chi squared 65.10 for 57 d.o.f.).  All the quoted errors\nare at the 90% confidence level.\n\nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/1040123/BA/\n\n[GCN OPS NOTE(04apr21): The word \"DRAFT:\" was removed fron the SUBJECT line.\nThe body of the Circular does contain the author's final text.]",
  "circularId": 29761,
  "createdOn": 1617569479000,
  "email": "amy.y.lien@nasa.gov",
  "subject": "GRB 210402A: Swift-BAT refined analysis",
  "submitter": "Amy Lien at GSFC  <amy.y.lien@nasa.gov>",
  "eventId": "GRB 210402A"
}