TITLE: GCN CIRCULAR NUMBER: 43121 SUBJECT: GRB 251214D: GECAM-B observation of a long burst DATE: 25/12/15 13:47:03 GMT FROM: Xinghao Luo at SVOM/GRM <2952704891@qq.com> Xing-Hao Luo, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team: GECAM-B was triggered on-ground by GRB 251214D, at 2025-12-14T21:24:17.950 UTC (denoted as T0), which is also detected by AstroSat/CZTI (A. Arya et.al., GCN #43109). According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 28.5 +6.5/-5.0 s. The GECAM-B light curve can be found here: https://www.bursthub.cn//admin/static/gecambgrb251214D.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). View this GCN Circular online at https://gcn.nasa.gov/circulars/43121. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...