GRB 261108B
GCN Circular 46205
Subject
GRB 261108B: Insight-HXMT/HE detection
Date
2026-11-09T11:11:05Z (2 hours ago)
From
Xinghao Luo at IHEP <2952704891@qq.com>
Via
Web form
Xing-Hao Luo, Chen-Wei Wang, Chao Zheng, and Shao-Lin Xiong (IHEP) report on behalf of the Insight-HXMT team:
At 2026-11-08T05:37:39.200 (T0), Insight-HXMT/HE detected the GRB 261108B, which is also detected by Fermi/GBM (Fermi GBM team, GCN#46195).
The Insight-HXMT/HE light curve mainly consists of multiple pulses with a T90 of 18.6 +2.2/-1.0 s. The 1s peak rate, measured from T0+0.01 s, is 4184 cnts/sec. Insight-HXMT/HE detected a total of 11058 counts from this burst.
The HXMT/HE light curve can be found here:
https://www.bursthub.cn/gcn/2026/hxmtgrb261108B.png
All measurements above are made with the CsI detectors of Insight-HXMT/HE operating in the regular mode with the energy range of about 60-900 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope.
Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://hxmten.ihep.ac.cn/
GCN Circular 46195
Subject
GRB 261108B: Fermi GBM Final Localization Correction
Date
2026-11-08T16:12:07Z (21 hours ago)
From
A. Holzmann Airasca at University of Trento and INFN Bari <a.holzmannairasca@unitn.it>
Via
Web form
The Fermi GBM team reports the detection of a likely LONG GRB
"At 05:37:34.86 UT on 08 November 2026, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 261108B (trigger 815809059/261108234).
This trigger was initially classified as Distant Particles by the flight software,
but is in fact a GRB.
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 264.86, Dec = 80.18 (J2000 degrees, equivalent to J2000 17h 39m, +80d 10'),
with a statistical uncertainty of 1.57 degrees.
The angle from the Fermi LAT boresight is 62 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261108234/quicklook/glg_skymap_all_bn261108234.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261108234/quicklook/glg_healpix_all_bn261108234.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261108234/quicklook/glg_lc_medres34_bn261108234.gif"