TITLE:   GCN CIRCULAR
NUMBER:  32023
SUBJECT: GRB 220511A: Swift/BAT-GUANO arcminute localization
DATE:    22/05/11 22:15:07 GMT
FROM:    Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>

James DeLaunay (U Alabama), Aaron Tohuvavohu (U Toronto), Jamie A.
Kennea (PSU), Gayathri Raman (PSU) report:

Swift/BAT did not trigger on GRB 220511A (T0: 2022-05-11T13:47:57
UTC, Fermi/GBM GCN 32018, INTEGRAL/SPI-ACS trig#9912, GECAM trig #
utn220511_134156_GECAMb, AGILE GCN 32021).

The GECAM and INTEGRAL notices, 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 ~5 seconds.
The burst occurred during a Swift slew.
The burst location was found in a mosaiced slew image with an SNR of ~10.

The BAT position is
RA, Dec = 287.446, 17.739 deg which is
   RA(J2000)  = 19h 09m 47.04s
   Dec(J2000) =  17d 44′ 20.4″
with an estimated uncertainty of 7 arcmin.

This position is consistent with the Ferm/GBM localization (GCN 32018).

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 b
found at: https://www.swift.psu.edu/guano/