TITLE: GCN CIRCULAR NUMBER: 45939 SUBJECT: GRB 261011A: GECAM-B observation DATE: 26/10/13 12:29:42 GMT FROM: Jin-Ye Luo Jin-Ye Luo, Chen-Wei Wang, Yue Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team: GECAM-B was triggered on-ground by GRB 261011A at 2026-10-11T13:49:15.250 UTC (denoted as T0), which is also detected by SVOM/ECLAIRs (Huang et al., GCN #45895), Swift/BAT (Cenko et al., GCN #45896; Barthelmy et al., GCN #45930), and Konus-Wind (Ridnaia et al., GCN #45924). According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of muplti-pulses with a duration (T90) of 40 +21/-9 s. The GECAM-B light curve can be found here: https://www.bursthub.cn/gcn/2026/gecambgrb261011A.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).