TITLE: GCN CIRCULAR NUMBER: 31074 SUBJECT: GRB 211110A: GECAM detection DATE: 21/11/11 07:22:25 GMT FROM: Shenglun Xie at IHEP <xiesl@ihep.ac.cn> S. L. Xie, S. L. Xiong, S. Xiao, C. Cai, X. Y. Zhao, Y. Huang, X. Y. Song, J. C. Liu, Y. Q. Zhang, Y. Zhao, Z. W. Guo, C. Zheng, W. C. Xue, C. Y. Li, C. W. Wang, Q. B. Yi, B. X. Zhang, P. Zhang, W. X. Peng, R. Qiao, D. Y. Guo, X. B. Li, X. Ma, P. Wang, J. Wang, Z. Zhang, S. J. Zheng, W. Chen, J. J. He, G. Y. Zhao, Y. Q. Du, H. Wu, J. Liang, Q. Luo, X. L. Zhang, L. M. Song, F. J. Lu, S. N. Zhang (IHEP), report on behalf of GECAM team: During the commissioning phase, GECAM-B was triggered in-flight by a long burst, GRB 211110A, at 2021-11-10T03:26:29.600 UTC (denoted as T0). GECAM alert data was downlinked to the ground through the short message service of BeiDou Navigation Satellite System (BDS) within ~60 s after T0. According to the BDS alert data, this burst mainly consists of a broad pulse with a duration of about 15 s. The GECAM light curve could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/multiLCvsE_2021-11-10T033A263A28.4... Using the automatic on-ground localization pipeline with the BDS alert data, GECAM-B localized this burst to the following position (J2000): Ra: 324.19 deg Dec: -3.15 deg Err: 7.59 deg (1-sigma, statistical only) The current systematic error of location is estimated to be several degrees which could be minimized by the ongoing calibration. The GECAM preliminary location could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_skymap_bdm_90213989_V01.png Please note that all GECAM results here are preliminary. The final analysis will be published in journal papers or GECAM online catalog. Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time), which was funded by the Chinese Academy of Sciences (CAS).