TITLE:   GCN CIRCULAR
NUMBER:  45802
SUBJECT: GRB 260930B: GECAM-B detection of a burst
DATE:    26/10/03 07:12:09 GMT
FROM:    yzh807926@163.com

Zheng-Hang Yu, Chao Zheng, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:

GECAM-B was triggered in-flight by a burst GRB 260930B at 2026-09-30T18:56:57.900 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #45789). According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of a pulse with a duration (T90) of 1.30 +1.55/-1.20 s. 

The on-ground localization of GECAM-B is:
Ra: 326.3 deg   
Dec: 24.1 deg
Err: 8.6 deg (1-sigma, statistical only)

The GECAM-B light curve can be found here:
https://www.bursthub.cn/gcn/2026/9/gecambgrb260930B.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).