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GCN Circular 36672

Subject
GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
Date
2024-06-16T01:36:09Z (a month ago)
From
Aaron Tohuvavohu at University of Toronto <aaron.tohu@gmail.com>
Via
Web form
James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Jamie A. Kennea
(PSU), Samuele Ronchini (PSU), Gayathri Raman (PSU), Tyler Parsotan (GSFC) report:

Swift/BAT did not localize GRB 240615A onboard (T0: 2024-06-15T17:51:45 UTC, Fermi GCN 36671).

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 < 0.1 seconds.
The burst occurred during a Swift slew.
A confident location is found for the burst with SNR of 12.

The BAT position is
RA, Dec = 326.1413, +38.5948 deg which is
   RA(J2000)  = 21h 44m 33.91s
   Dec(J2000) =  +38d 35’ 41.3″
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: https://www.swift.psu.edu/guano/

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