{
  "bibcode": "2020GCN.27444....1D",
  "body": "James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), and Jamie Kennea\n(PSU) report:\n\nSwift/BAT did not trigger on GRB 200325A.\n\nThe Fermi/GBM Flight-Position notice, distributed at T0+8 seconds,\nfrom the Fermi/GBM detected GRB 200325A (GCN. 27434), as well as the\nINTEGRAL SPI-ACS notice (Trig #8558) distributed at T0+44 seconds,\nboth triggered the Swift Mission Operations Center operated Gamma-ray\nUrgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al.\n2020, in prep). GRB 200325A was also detected by AGILE/MCAL (GCN.\n27437) and AstroSat CZTI (GCN. 27438).\n\nThe GUANO is a fully autonomous, extremely low latency, spacecraft\ncommanding pipeline designed for targeted recovery of BAT event mode\ndata around the times of compelling astrophysical events to enable\nmore sensitive GRB searches.\n\nUpon trigger by these notices, GUANO sent a command to the Swift Burst\nAlert Telescope (BAT) to save 200 seconds of BAT event-mode data from\n[-50,+150] seconds around the time of GRB 200228A.\n\nAll the requested event mode data was delivered to the ground.\n\nIn a ground analysis of the data, using the normal BAT imaging\ntechnique, we detect GRB 200228A with a SNR of 7.5.\n\nWith a more sophisticated maximum likelihood analysis (DeLaunay et\nal.,  2020 in prep.) on the event-mode data we detect GRB 200325A more\nconfidently, with a square root of the test statistic, sqrt(TS), of\n21.7. The sqrt(TS) behaves similarly to SNR.\nThe detected duration is ~1.1s.\n\nThe BAT ground-calculated position is\nRA, Dec = 31.7203, -31.816 deg which is\n   RA(J2000)  = 2h 6m 52.8s\n   Dec(J2000) =  -31d 48��� 57.60���\nwith an uncertainty of 4 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 8.2%.\n\nThis arcminute location is consistent with the localization region\ndistributed by the Fermi/GBM team (GCN. 27434), lying on the 75%\ncontainment contour.\nDue to the very low partial coding, we stress that this localization,\nwhile significant, has some additional unquantified uncertainties\nassociated with it.\n\nNo XRT or UVOT follow-up will take place due to the source���s proximity\nto the sun (1.5 hours).\nWe encourage follow-up from instruments capable of observing near the sun.\n\nA live reporting of Swift/BAT event data recovered by GUANO can be found\n at: https://www.swift.psu.edu/guano/",
  "circularId": 27444,
  "createdOn": 1585183943000,
  "email": "aaron.tohu@gmail.com",
  "subject": "GRB 200325A: Swift/BAT detection and probable arcminute localization of a short GRB from GUANO",
  "submitter": "Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>",
  "eventId": "GRB 200325A"
}