TITLE: GCN CIRCULAR NUMBER: 22341 SUBJECT: GRB 180111A: Insight-HXMT/HE observation DATE: 18/01/15 12:20:59 GMT FROM: Shaolin Xiong at IHEP G. Li, S. L. Xiong, X. B. Li, C. K. Li, J. Y. Liao, C. Z. Liu, X. F. Li, Z. W. Li, X. F. Lu, Z. Chang, J. L. Zhao, A. M. Zhang, 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 2018-01-11T16:42:06 (T0), Insight-HXMT/HE detected GRB 180111A (trigger ID: HEB180111695) in a routine search of the data,which is also triggered by Swift/BAT (Lien et al.,GCN 22318),AGILE/MCAL(Verrecchia et al.,GCN 22321),and CALET(Asaoka et al.,GCN 22333). The Insight-HXMT/HE light curve mainly consists of multi-pulses with a duration (T90) of 19.94 s measured from T0+0.185 s. The 500-ms peak rate, measured from T0+0.422 s, is 2332.29 cnts/sec. The total counts from this burst is 13972.02 counts. URL_LC: http://www.hxmt.org/images/GRB/HEB180111695_lc.jpg All measurements above are made with the CsI detectors operating in the GRB mode, in which the energy range is increased to about 200 - 3000 keV (record energy), compared to the normal mode of 80 - 800 keV. 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 .