TITLE: GCN CIRCULAR NUMBER: 22353 SUBJECT: GRB 180112A: Insight-HXMT/HE detection/observation DATE: 18/01/16 14:16:28 GMT FROM: Xufang Li at IHEP C. Z. Liu, X. F. Li, S. L. Xiong, X. B. Li, C. K. Li, Z. W. Li, Z. Chang, J. L. Zhao, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),report on behalf of the Insight-HXMT team: At 16:30:38.00 UT on January 12 2018, the Insight-HXMT/HE detected GRB 180112A(Insight-HXMT internal trigger ID: HEB180112687 and HEB180112689, corresponding to two main pulses) in a routine search of the data, which was also triggered by Swift/BAT and Integral/SPI-ACS and CALET/CGBM. It's a pulsating GRB event. The Insight-HXMT light curve consists of two bursts triggered respectively at 16:30:38.00 UT and 16:32:56.00 UT, each of the two bursts consists of multiple pulses. The GRB event totally has a duration (T90) of 151.788 s measured from T0-5.2385 s. The 1s peak rate, measured from T0+139.541 s, is 1383.0 cnts/sec. The total counts from this GRB event is 4935.2 counts. URL_LC: http://www.hxmt.org/images/GRB/HEB180112687_lc.jpg All measurements above are made with the CsI detectors operating in the GRB mode with the energy range of about 200-3000 keV (record energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope. The analysis results presented above are preliminary; final results will be published elsewhere. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://www.hxmt.org/index.php/enhome .