TITLE:   GCN CIRCULAR
NUMBER:  41487
SUBJECT: GRB 250821A: GECAM-B detection
DATE:    25/08/22 07:46:56 GMT
FROM:    Chenwei Wang at IHEP <cwwang@ihep.ac.cn>

Chen-Wei Wang, Shao-Lin Xiong and Yue Huang (IHEP) report on behalf of GECAM team:

GECAM-B was triggered on-ground by GRB 250821A at 2025-08-21T10:46:18.000 UTC (denoted as T0), which is also detected by Swift/BAT (S. Dichiara et al., GCN#41462). According to the GECAM-B light curves in about 40-6000 keV, this burst mainly consists of a single pulse with a duration (T90) of 1.5 +1.5/-0.5 s.

The GECAM-B light curve can be found here:
https://www.bursthub.cn//admin/static/gecamgrb250821A.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).