GRB 210131A: GECAM detection

During the commissioning phase, the ground search of GECAM-B data found a long burst, GRB 210131A, at 2021-01-31T12:29:12.000 UTC (T0). According to the GECAM-B light curves in about 8 keV-4 MeV, this burst mainly consists of a broad pulse with a duration (T90) of 8.7 +/- 0.4 s. The 1-s peak counts rate is about 591 cps while the total counts is about 3814 counts. Although the in-flight calibration of energy response and localization has not been finalized yet, GECAM-B localized this burst to the following position (J2000): Ra: 35.17 deg Dec: 25.23 deg Err: 7.39 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 light curve could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/utn210131_122912_GECAMb_v0.pdf 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).