TITLE:   GCN CIRCULAR
NUMBER:  45023
SUBJECT: GRB 260616B/EP260616a: Insight-HXMT/HE detection
DATE:    26/06/23 06:06:51 GMT
FROM:    yzh807926@163.com

GRB 260616B/EP260616a: Insight-HXMT/HE detection

Zheng-Hang Yu, Chen-Wei Wang, Chao Zheng, and Shao-Lin Xiong (IHEP) report on behalf of the Insight-HXMT team:

At 2026-06-16T07:05:26.950 (T0), Insight-HXMT/HE detected GRB 260616B/EP260616a, which is also detected by Fermi/GBM (Fermi GBM Team, GCN #44953), AstroSat CZTI (A. Arya et al., GCN #44997) and SVOM/GRM (Yu et al., GCN #45011).

The Insight-HXMT/HE light curve mainly consists of two pulses with a T90 of 11.6 +1.4/-0.3 s. The 1 s peak rate, measured from T0-0.25 s, is 2154 cnts/sec. Insight-HXMT/HE detected a total of 8808 counts from this burst.

The Insight-HXMT/HE light curve can be found here:
https://www.bursthub.cn//admin/static/hxmtgrb260616B.png

All measurements above are made with the CsI detectors of Insight-HXMT/HE operating in the normal gain mode with the energy range of about 6-900 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