GCN Circular 35060
W. C. Xue, S. L. Xiong, X. B. Li and C. K. Li report on behalf of the Insight-HXMT team: At 2023-11-15T15:36:21.200 (T0), Insight-HXMT/HE detected GRB 231115A (trigger ID: HEB231115650) in a routine search of the data, which was also observed by Fermi/GBM (Fermi GBM Team, GCN 35035 & 35044), INTEGRAL (P. D'Avanzo et al., GCN 35036, S. Mereghetti et al. GCN 35037) and Glowbug (C. C. Cheung et al., GCN 35045). This burst is probably a giant flare from a magnetar in the nearby galaxy M82. The Insight-HXMT/HE light curve mainly consists of single pulse with a duration (T90) of 0.08 s measured from T0-0.01 s. The 1-ms peak rate, measured from T0-0.01 s, is 16611 cnts/sec. The total counts from this burst is 210 counts. URL_LC: https://twikinew.ihep.ac.cn/pubhxmt/HXMT/GRBList/HEB231115650_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 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.