{
  "bibcode": "2021GCN.30302....1D",
  "body": "James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Jamie A. Kennea\n(PSU), Gayathri Raman (PSU) report:\n\nSwift/BAT did not trigger on GRB 210622A (T0: 2021-06-22 01:32:35.9\nUTC, Fermi/GBM GCN 30297).\n\nThe Fermi/GBM notice, distributed in near real-time, triggered the\nSwift Mission Operations Center operated Gamma-ray Urgent Archiver for\nNovel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).\n\nUpon trigger by this notice, 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 the burst. All the requested\nevent mode data was delivered to the ground.\n\nThe burst is detected in BAT with a duration of at least 25 seconds.\nWe note this is different from the prompt GBM classification as ���likely short���.\nThe burst morphology consists of a first bright, short, hard, peak\nfollowed by longer emission with weaker flares.\n\nWith a maximum likelihood analysis (DeLaunay et al. 2021, in prep.) on\nthe event-mode data we detect a location for the burst with a square\nroot of the test statistic, sqrt(TS), of 18.8. The sqrt(TS) behaves\nsimilarly to SNR.\nUsing the normal BAT imaging technique, we find the same location for\nthe GRB with an SNR of 8.1.\n\nThe BAT position is\nRA, Dec = 233.117, -26.213 deg which is\n   RA(J2000)  = 15h 32m 28.10s\n   Dec(J2000) =  -26d 12��� 47.5���\nwith an estimated uncertainty of 2.5 arcmin.\n\nThis position is consistent with the Ferm/GBM localization (GCN 30297).\n\nXRT and UVOT follow-up has been requested. Prompt followup by Swift is\ndelayed due to visibility constraints. Results of follow-up\nobservations will be reported in future circulars.\n\nGUANO 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\nA live reporting of Swift/BAT event data recovered by GUANO can be\nfound at: https://www.swift.psu.edu/guano/",
  "circularId": 30302,
  "createdOn": 1624370379000,
  "email": "aaron.tohu@gmail.com",
  "subject": "GRB 210622A: Swift/BAT-GUANO detection and arcminute localization of a long burst",
  "submitter": "Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>",
  "eventId": "GRB 210622A"
}