TITLE: GCN CIRCULAR NUMBER: 25879 SUBJECT: GRB 190928A: Insight-HXMT/HE detection DATE: 19/09/30 15:50:41 GMT FROM: Qi Luo at IHEP Q. Luo, C. Cai, S. Xiao, Q. B. Yi, Y. G. Zheng, Y. Huang, C. K. Li, X. B. Li, G. Li, J. Y. Liao, S. L. Xiong, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, 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, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team: At 2019-09-28T13:12:14.00 (T0), Insight-HXMT/HE detected GRB 190928A (trigger ID: HEB190928550) in a routine search of the data, which was also reported by AGILE/MCAL (GCN #25859), IPN triangulation (GCN #25864), CALET/GBM (GCN #25865) and Konus-Wind (GCN #25868). The Insight-HXMT/HE light curve mainly consists of multiple pulses with a duration (T90) of 31.10 s measured from T0+78.39 s. The 1-ms peak rate, measured from T0+102.88 s, is 23712 cnts/sec. The total counts from this burst is 152469 counts. The data of Insight-HXMT/HE suffers saturation in the brightest part. URL_LC: http://www.hxmt.org/images/GRB/HEB190928550_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 (deposited 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. 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.