TITLE:   GCN CIRCULAR
NUMBER:  46205
SUBJECT: GRB 261108B: Insight-HXMT/HE detection
DATE:    26/11/09 11:11:05 GMT
FROM:    Xinghao Luo at IHEP <2952704891@qq.com>

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/