TITLE: GCN CIRCULAR NUMBER: 43055 SUBJECT: GRB 251208C: GECAM-B observation of a short burst DATE: 25/12/09 16:16:20 GMT FROM: Yue Wang Yue Wang, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team: GECAM-B was triggered on-ground by GRB 251208C, at 2025-12-08T12:52:32.600 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #43030) and SVOM/GRM (Yue Wang et al., GCN #43041). 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 0.3 +0.2/-0.2 s. The GECAM-B light curve can be found here: https://www.bursthub.cn//admin/static/gecambgrb251208C.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).