TITLE:   GCN CIRCULAR
NUMBER:  42572
SUBJECT: GRB 251103A: Insight-HXMT detection
DATE:    25/11/04 10:49:35 GMT
FROM:    renyz16607@163.com

GRB 251103A: Insight-HXMT detection
Yang-Zhao Ren, Chen-Wei Wang, Cheng-Kui Li, Shao-Lin Xiong, and Chao Zheng report on behalf of the Insight-HXMT team:

At 2025-11-03T04:46:28.000 (T0), Insight-HXMT/HE detected the burst GRB 251103A, which is also detected by SVOM/ECLAIRs (Hu et al., GCN#42534), Fermi/GBM (Fermi GBM team, GCN #42536), SVOM/GRM (Wang et al., GCN#42552). 

The Insight-HXMT/HE light curve mainly consists of a single pulse with a T90 of 5.5 +2.5/-2.0 s. The 1s peak rate, measured from T0+0.25 s, is 2447 cnts/sec. The total counts from this burst is 5414 counts.  

The HXMT/HE light curve can be found here: 
https://www.bursthub.cn//admin/static/hxmtgrb251103A.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