TITLE: GCN CIRCULAR NUMBER: 30472 SUBJECT: GRB 210719A: GECAM detection DATE: 21/07/20 16:01:57 GMT FROM: Shenglun Xie at IHEP X. L. Zhang, W. C. Xue, S. Xiao, S. L. Xiong, X. Y. Zhao, X. Y. Song, C. Cai, Y. Huang, S. L. Xie, J. C. Liu, C. Y. Li, Y. Q. Zhang, Y. Zhao, Z. W. Guo, C. Zheng, Z. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo, J. J. He, B. Li, C. Li, J. H. Li, Q. X. Li, X. B. Li, X. Q. Li, Y. G. Li, X. H. Liang, J. Y. Liao, J. C. Liu, X. J. Liu, Y. Q. Liu, F. J. Lu, Q. Luo, X. Ma, G. Ou, W. X. Peng, R. Qiao, D. L. Shi, J. Y. Shi, L. M. Song, G. X. Sun, X. L. Sun, Y. L. Tuo, C. W. Wang, J. Z. Wang, P. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, M. Yao, Q. B. Yi, B. X. Zhang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang, K. Zhang, P. Zhang, S. N. Zhang, Z. Zhang, S. Y. Zhao, S. J. Zheng, X. Zhou (IHEP), report on behalf of GECAM team: During the commissioning phase, GECAM-B was triggered in-flight by a long burst, GRB 210719A, at 2021-07-19T02:24:59.500 UTC (denoted as T0). According to the GECAM-B light curves in about 15-3500 keV, this burst mainly consists of multiple pulses with a duration about 400 s. The GECAM light curve could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/LC_2021-07-19T02_24_59.500.png GECAM-B localized this burst to the following position (J2000): Ra: 82.64 deg Dec: 51.02 deg Err: 5.16 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 location map could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/tn210719_022608_location.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).