TITLE:   GCN CIRCULAR
NUMBER:  37606
SUBJECT: Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
DATE:    24/09/25 06:13:38 GMT
FROM:    yqzhang_cl@163.com

Ce Cai (HEBNU), Xiao-Bo Li (IHEP), Shao-Lin Xiong (IHEP), Wang-Chen Xue (IHEP), 
Shuang-Nan Zhang (IHEP), Lin Lin (BNU) report on behalf of the Insight-HXMT team:

1E 1841-045 / Kes 73 has been in an active phase since August 20, 2024, 
as reported by Swift/BAT (DeLaunay et al., GCN 37211, Dichiara et al., GCN 37222),  
Fermi/GBM (Roberts et al., GCN 37234), GECAM-B (Zhang et al., GCN 37240), 
SVOM/GRM (Wang et al., GCN 37297). From 2024-08-23 16:13:43 UTC to 
2024-08-29 10:02:44 UTC, Insight-HXMT observed 1E 1841-045 / Kes 73 under 
a public ToO (P0714005). Using different time resolutions (5 ms, 10 ms, 20 ms and 40 ms), 
we searched the data of Insight-HXMT/HE (NaI, 30-250 keV), ME (10-30 keV) and 
LE (1-10 keV). Assuming that bursts were separated by at least 1 second, Insight-HXMT 
detected five bursts during the six-day observation period. The X-ray bursts from this 
magnetar found in this public ToO observation are as follows:

Date and Time in UTC
2024-08-24T08:04:52.105
2024-08-25T00:00:13.655
2024-08-25T18:53:45.230
2024-08-26T15:44:10.390
2024-08-27T09:08:56.020

Detailed spectral and temporal analysis of these bursts will be reported elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, 
jointly funded by the China National Space Administration (CNSA) and the Chinese 
Academy of Sciences (CAS). More information about it could be found at: 
http://hxmten.ihep.ac.cn/