//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31528 SUBJECT: GRB 220127A: GECAM detection DATE: 22/01/28 04:34:33 GMT FROM: Shenglun Xie at IHEP S. L. Xie, S. L. Xiong, S. Xiao, Y. Q. Zhang, C. Cai, P. Zhang, C. Y. Li, J. C. Liu, X. Y. Zhao, Y. Huang, X. Y. Song, C. Zheng, Y. Zhao, Z. W. Guo, W. C. Xue, C. W. Wang, Q. B. Yi, B. X. Zhang, W. X. Peng, R. Qiao, D. Y. Guo, X. B. Li, X. Ma, L. M. Song, 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, H. M. Zhang, Z. H. An, M. Gao, K. Gong, B. Li, C. Li, J. H. Li, X. Q. Li, Y. G. Li, X. H. Liang, X. J. Liu, Y. Q. Liu, X. L. Sun, Y. L. Tuo, J. Z. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, X. Zhou, 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 220127A, at 2022-01-27T18:53:26.100 UTC (denoted as T0), which was also observed by INTEGRAL/SPI-ACS(TrigID=9654), WIND-KONUS. 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 single pulse with a duration of about 0.2 s. The GECAM light curve could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_lc_grd_all_combine_97008806.png Using the automatic on-ground localization pipeline with the BDS alert data, GECAM-B localized this burst to the following position (J2000): Ra: 306.36 deg Dec: -44.3 deg Err: 5.14 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_flt_97008806.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).