TITLE:   GCN CIRCULAR
NUMBER:  42155
SUBJECT: GRB 251006B: Insight-HXMT detection
DATE:    25/10/08 04:38:08 GMT
FROM:    Chenwei Wang at IHEP <cwwang@ihep.ac.cn>

Chen-Wei Wang, Yue Wang, Cheng-Kui Li, Shao-Lin Xiong, and Chao Zheng report on behalf of the Insight-HXMT team:

At 2025-10-06T20:05:04.350 (T0), Insight-HXMT/HE detected the burst GRB 251006B, which is also detected by Fermi/GBM (Fermi GBM team, GCN#42131), EP (Yin et al., GCN#42137) and SVOM/GRM (Wang et al., GCN#42139).

The Insight-HXMT/HE light curve mainly consists of multi-pulses with a T90 of 4.6 +1.1/-0.8 s. The 1s peak rate, measured from T0-0.1 s, is 3694 cnts/sec. The total counts from this burst is 5990 counts.

The HXMT/HE light curve can be found here:
https://www.bursthub.cn//admin/static/hxmtgrb251006B.png

All measurements above are made with the CsI detectors 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://www.hxmt.org.