TITLE:   GCN CIRCULAR
NUMBER:  36896
SUBJECT: GRB 240716A: GECAM-B detection of a long burst
DATE:    24/07/17 12:19:11 GMT
FROM:    wenlongzhang2018@163.com

Wen-Long Zhang, Shao-Lin Xiong, Shi-Jie Zheng, Yue Huang, Yan-Qiu Zhang, Wen-Jun Tan, Chen-Wei Wang, Peng Zhang report on behalf of the GECAM team:

GECAM-B was triggered in-flight by a long burst, GRB 240716A, at 2024-07-16T10:21:35.300 UTC (T0), which was also observed by SVOM/GRM (GCN # 36895). 

According to the realtime alert data downlinked through the BeiDou Navigation Satellite System (BDS), the GECAM-B light curve shows a long pulse with a total duration of ~8 sec (30-1020 keV). 

The GECAM-B in-flight location (J2000) is: 
Ra: 116.43 deg   
Dec: 46.57 deg
Err: 2.97 deg (1-sigma, statistical only)

The time-averaged spectrum of GECAM-B realtime data from about T0-0.5 to T0+3.5s could be adequately fit by a Band function with a fluence about 4.16E-6 erg/cm^2 in 20-1000 keV.

The GECAM-B light curve can be found here:
http://www.bursthub.cn//admin/static/gecamgrb240716A.png

We note that these results are based on realtime alert data and thus very preliminary. Refined analysis will be reported later.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS).