TITLE: GCN CIRCULAR NUMBER: 22316 SUBJECT: GRB 171230B: Insight-HXMT/HE detection DATE: 18/01/11 09:17:11 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 22:55:34.00 UT on December 30 2017, the Insight-HXMT/HE detected GRB 171230B(trigger ID: HEB171230955) in a routine search of the data, which was also triggered by Fermi/GBM and Integral. It's a long GRB. The Insight-HXMT light curve consists of multiple pulses with a duration (T90) of 40.891 s measured from T0+0.065 s. The 1s peak rate, measured from T0+0.929 s, is 1261.5 cnts/sec. The total counts from this burst is 13212.3 counts. URL_LC: http://www.hxmt.org/images/GRB/HEB171230955_lc.jpg All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 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. [GCN OPS NOTE(11jan18): Per author's request, the GRB in the Subject-line was corrected from 171223B to 121730B.]