TITLE: GCN CIRCULAR NUMBER: 44281 SUBJECT: GRB 260412A: GECAM-B observation of a long burst DATE: 26/04/13 06:10:54 GMT FROM: Xinghao Luo at IHEP <2952704891@qq.com> Xing-Hao Luo, Chao Zheng, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team: GECAM-B was triggered on-ground by GRB 260412A, at 2026-04-12T06:13:49.000 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #44275) and SVOM/ECLAIRs (Ziqi Wang et.al., GCN#44276). According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 32 +6/-4 s. The GECAM-B light curve can be found here: https://www.bursthub.cn//admin/static/gecambgrb260412A.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).