GCN Circular 29050

Y. Q. Zhang, C. Cai, J. C. Liu, Q. Luo, S. Xiao, 
W. C. Xue, Q. B. Yi, C. Zheng���Y. Huang, C. K. Li, 
G. Li, X. B. Li, J. Y. Liao, X. Y. Song, 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 2020-12-09T05:44:52.53 (T0), Insight-HXMT/HE detected 
GRB 201209A (trigger ID: HEB201209239) in a routine search of the data, 
which also triggered Swift/BAT (Gropp J. et al., GCN #29005) and 
AstroSat/CZTI ( Nadella D. et al., GCN #29011)..

The Insight-HXMT/HE light curve mainly consists of multiple 
pulses with a duration (T90) of 9.99 s measured from T0-1.09 s. 
The 1-ms peak rate, measured from T0+7.16 s, is 778 cnts/sec. 
The total counts from this burst is 2926 counts. 
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB201209239_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.