GRB 231224A
GCN Circular 35426
Subject
GRB 231224A: Fermi GBM Final Real-time Localization
Date
2023-12-24T20:59:57Z (a year ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely SHORT GRB
At 20:49:15 UT on 24 Dec 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 231224A (trigger 725143760.994196 / 231224868).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 102.3, Dec = -71.2 (J2000 degrees, equivalent to J2000 06h 49m, -71d 12'), with a statistical uncertainty of 11.9 degrees.
The angle from the Fermi LAT boresight is 24.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn231224868/quicklook/glg_skymap_all_bn231224868.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn231224868/quicklook/glg_healpix_all_bn231224868.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn231224868/quicklook/glg_lc_medres34_bn231224868.gif
GCN Circular 35430
Subject
IPN triangulation of GRB 231224A (short)
Date
2023-12-27T12:51:08Z (a year ago)
From
Dmitry Svinkin at Ioffe Institute <dmitrysvinkin@gmail.com>
Via
Web form
D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
on behalf of the IPN,
A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,
and
E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
report:
The short-duration GRB 231224A
(Fermi-GBM detection: The Fermi GBM team, GCN 35426)
was detected by Fermi (GBM trigger 725143760) and
INTEGRAL (SPI-ACS) at about 74956 s UT (20:49:16).
We have triangulated it to a GBM-SPI-ACS annulus centered at
RA(2000)=230.929 deg (15h 23m 43s) Dec(2000)=-83.517 deg (-83d 30' 60"),
whose radius is 32.644 +/- 5.664 deg (3 sigma).
The annulus combined with the Fermi-GBM final position (GCN 35426;
glg_healpix_all_bn231224868_v00) gives ~792 sq. deg (3 sigma) localization region.
A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB231224_T74955/IPN/