TITLE: GCN CIRCULAR NUMBER: 25315 SUBJECT: HAWC-190806A: Upper limits from Insight-HXMT/HE observations DATE: 19/08/13 00:53:58 GMT FROM: YaoGuang Zheng at IHEP Y. G. Zheng, C. Cai, Q. Luo, S. Xiao, Q. B. Yi, Y. Huang, C. K. Li, G. Li, X. B. 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: Insight-HXMT was taking data normally around the trigger time (T0=2019-08-06T13:20:48.00 UTC) of HAWC-190806A event (GCN #25284), which was monitored without any occultation by the Earth. Within T0 +/- 100 s, no significant excess events (SNR > 3 sigma) are found in a search of the Insight-HXMT/HE raw light curves. Assuming the counterpart GRB with three typical GRB Band spectral models, two typical duration timescales (1 s, 10 s) from the center of the position of the alert is (RA=78.125 deg, DEC=6.589 deg), the 5-sigma upper-limits fluence (0.2 - 5 MeV, incident energy) are reported below: Band model 1 (alpha=-1.9, beta=-3.7, Ep=70 keV): 1 s: 1.8e-08 erg cm^-2 10 s: 1.8e-07 erg cm^-2 Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV): 1 s: 3.6e-08 erg cm^-2 10 s: 3.3e-07 erg cm^-2 Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV): 1 s: 1.8e-07 erg cm^-2 10 s: 1.2e-06 erg cm^-2 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 spacecraft.