TITLE:   GCN CIRCULAR
NUMBER:  30437
SUBJECT: GECAM detection of a short burst from SGR J1935+2154
DATE:    21/07/10 13:52:17 GMT
FROM:    Wangchen Xue at IHEP  <xuewc@ihep.ac.cn>

W. C. Xue, S. Xiao, S. L. Xiong, X. Y. Zhao, X. Y. Song, C. Cai, Y. Huang,
S. L. Xie, J. C. Liu, C. Y. Li, Y. Q. Zhang,  Y. Zhao, Z. W. Guo, C. Zheng,
Z. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo, J. J. He,
B. Li, C. Li, J. H. Li, Q. X. Li, X. B. Li, X. Q. Li, Y. G. Li, X. H. Liang,
J. Y. Liao, J. C. Liu, X. J. Liu, Y. Q. Liu, F. J. Lu, Q. Luo, X. Ma,
G. Ou, W. X. Peng, R. Qiao, D. L. Shi, J. Y. Shi, L. M. Song,
G. X. Sun, X. L. Sun, Y. L. Tuo, C. W. Wang, J. Z. Wang,
P. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, M. Yao, Q. B. Yi,
B. X. Zhang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang,
K. Zhang, P. Zhang, S. N. Zhang, Z. Zhang, S. Y. Zhao, S. J. Zheng,
X. Zhou (IHEP), report on behalf of GECAM team:

During the commissioning phase, GECAM-B was triggered in-flight by
a bright short burst (trig# 79592741) at 2021-07-10T05:05:41.450 UTC (T0),
Its alert data was promptly downlinked to the ground through the short
message service of BeiDou Navigation Satellite System (BDS). The time latency
of the first BeiDou message relative to the trigger time is about 1 minute.

According to the GECAM-B light curves in about 20-50 keV, this burst mainly
consists of a single pulse with a duration about 50 ms. The position is consistent
with SGR J1935+2154 within the error.

The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/79592741.45000005energys.pdf

Please note that all GECAM results here are preliminary. The final analysis
will be published in journal papers or GECAM online catalog.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in
Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time),
which was funded by the Chinese Academy of Sciences (CAS).