GCN Circular 23546

Q. Luo, 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, X. F. Lu, J. L. Zhao,
A. M. Zhang, Y. F. 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 2018-12-17T15:56:57.00 (T0), the Insight-HXMT/HE detected
GRB 181217A(trigger ID: HEB181217664) in a routine search of the data,
which was also triggered by Fermi/GBM (trigger_num:566755024).

The Insight-HXMT/HE light curve mainly consists of multiple 
pulses with a duration (T90) of 25.59 s measured from T0-0.28 s.
The 1-s peak rate, measured from T0+2.7660 s, is 498.6 cnts/sec.
The total counts from this burst is 6118.1 counts.
URL_LC: http://www.hxmt.org/images/GRB/HEB181217664_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
fundedjointly 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.