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GCN Circular 33027

GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
2022-12-06T21:12:13Z (a year ago)
Aaron Tohuvavohu at U Toronto <>
James DeLaunay (U Alabama), Aaron Tohuvavohu (U Toronto), Jamie A.
Kennea (PSU), Gayathri Raman (PSU), report:

Swift/BAT did not trigger on GRB 221206 (T0: 2022-12-06T12:22:47
UTC, Fermi/GBM GCN 33023).

The Fermi/GBM notice, distributed in near real-time, triggered the
Swift Mission Operations Center operated Gamma-ray Urgent Archiver for
Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).

Upon trigger by this notice, GUANO sent a command to the Swift Burst
Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from
[-50,+150] seconds around the time of the burst. All the requested
event mode data was delivered to the ground.

The burst is detected in BAT with a duration of ~12 seconds.
The burst occurred during a Swift slew.
A candidate location for the burst was found with an SNR of 6.6.

The BAT position is
RA, Dec = 251.155, +42.671 deg which is
   RA(J2000)  = 16h 44m 37.13s
   Dec(J2000) =  +42d 40��� 17.0���
with an estimated uncertainty of 4 arcmin.

This position is consistent with the Ferm/GBM localization (GCN 33023).
XRT and UVOT follow-up has been requested. Results of follow-up
observations will be reported in future circulars.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at:
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