////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  32726
SUBJECT: GRB 221013B: Fermi GBM Final Real-time Localization
DATE:    22/10/13 02:33:57 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely SHORT GRB

At 02:23:28 UT on 13 Oct 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221013B (trigger 687320613.487128 / 221013100).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 220.8, Dec = -36.3 (J2000 degrees, equivalent to J2000 14h 43m, -36d 17'), with a statistical uncertainty of 14.6 degrees.

The angle from the Fermi LAT boresight is 109.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221013100/quicklook/glg_skymap_all_bn221013100.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221013100/quicklook/glg_healpix_all_bn221013100.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221013100/quicklook/glg_lc_medres34_bn221013100.gif

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TITLE:   GCN CIRCULAR
NUMBER:  32798
SUBJECT: GRB 221013B: Swift/BAT-GUANO detection
DATE:    22/10/19 02:04:39 GMT
FROM:    Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>

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

Swift/BAT did not localize GRB 221013B onboard (T0: 2022-10-13T02:23:28
 UTC, Fermi/GBM GCN 32726).

The Fermi 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, 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 BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu,
arXiv:2111.01769), detects the burst with a sqrt(TS) of 9.2 in a 1.024
s analysis time bin.

NITRATES results, independently, are ambiguous with respect to whether
this burst originates from in or outside the BAT FOV, with DeltaLLHOut
of 3.3 and DeltaLLHPeak of 0.2.

See Section 9.1 and Figure 20 in the NITRATES paper for brief
descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and
DeltaLLHOut.

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/

////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  32810
SUBJECT: Fermi GBM trigger 687320613 / 221013100 (GRB 221013B) is not a GRB
DATE:    22/10/20 20:25:38 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres  (UAH) reports on behalf of the Fermi GBM Team:

“The Fermi Gamma-ray Burst Monitor (GBM) trigger 687320613 / 221013100  at
02:23:28 UT on 13 October 2022, classified as a GRB (GCN #32726), is in
fact not due to a GRB. This trigger is possibly related to a solar flare.

For Fermi GBM data and info, please visit the official Fermi GBM Support
Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/”