TITLE:   GCN CIRCULAR
NUMBER:  42183
SUBJECT: GRB 251007A: Insight-HXMT detection
DATE:    25/10/10 12:33:04 GMT
FROM:    Chenwei Wang at IHEP <cwwang@ihep.ac.cn>

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

At 2025-10-07T19:37:51.750 (T0), Insight-HXMT/HE detected the burst GRB 251007A, which is also detected by Swift/BAT (E. Ambrosi et al, GCN#42146), Glowbug (C.C. Cheun et al., GCN#42151), CALET/GBM (A. Yoshida et al., GCN#42156) and AstroSat (S. Salunke et al., GCN#42167).

The Insight-HXMT/HE light curve mainly consists of multi-pulses with a T90 of 57.4 +1.8/-16.2 s. The 1s peak rate, measured from T0+0.7 s, is 7246 cnts/sec. The total counts from this burst is 52938 counts.

The HXMT/HE light curve can be found here:
https://www.bursthub.cn//admin/static/hxmtgrb251007A.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.