TITLE:   GCN CIRCULAR
NUMBER:  42738
SUBJECT: GRB 251114B: GECAM-B detection of a short burst
DATE:    25/11/18 15:57:36 GMT
FROM:    zhangjinpeng@ihep.ac.cn

Jin-Peng Zhang, Chen-Wei Wang, Chao Zheng, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:

GECAM-B was triggered in-flight by a short burst, GRB 251114B, at 2025-11-14T20:38:30.100 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN#42687).

According to the GECAM-B light curves in about 40-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 3.4 +1.6/-2.0 s.

The GECAM-B light curve can be found here:
https://www.bursthub.cn//admin/static/gecambgrb251114B.png

The time-averaged spectrum from T0-2 s to T0+2 s is best fitted by a power law function. The power law index is -1.97 +0.18/-0.16. The event fluence (10-1000 keV) in this time interval is (2.32 +0.22/-0.24)E-06 erg/cm^2.

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).