TITLE:   GCN CIRCULAR
NUMBER:  44217
SUBJECT: GRB 260403A: GECAM-B observation of a long burst
DATE:    26/04/05 07:34:52 GMT
FROM:    Xinghao Luo at IHEP <2952704891@qq.com>

Xing-Hao Luo, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:

GECAM-B was triggered in-flight by GRB 260403A, at 2026-04-03T02:31:29.500 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #44195) and AstroSat CZTI (A. Goyal et.al., GCN#44202).

According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of a single pulse with a duration (T90) of  24.5 +3.0/-4.0 s.

The GECAM-B light curve can be found here:
https://www.bursthub.cn//admin/static/gecambgrb260403A.png

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission originally consists of two micro-satellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS).