TITLE:   GCN CIRCULAR
NUMBER:  37924
SUBJECT: GRB 241026A: GECAM detection
DATE:    24/10/28 08:29:21 GMT
FROM:    yqzhang_cl@163.com

Yan-Qiu Zhang (IHEP), Shao-Lin Xiong (IHEP), Chen-Wei Wang (IHEP) report on behalf of the GECAM team:

GECAM-B was triggered both in-flight and on-ground by a long burst, GRB 241026A, at 2024-10-26T22:42:31.200 UTC (T0), which was also detected by Fermi/GBM (Fermi GBM team, GCN #37894), Swift/BAT (A. Melandri et al., GCN #37896), SVOM/GRM (Yan-Qiu Zhang et al., GCN #37921) and EP/WXT (D. Y. Li et al., GCN #37909).

According to the GECAM-B light curves in about 6-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of about 14.9（+4.8,-3.6）s.
The time-averaged spectrum from T0-0.32 to T0+14.61 s could be fit by a power law with a fluence of about 6.67 (+0.36,-0.35) E-06 erg/cm^2 in 10-1000 keV.

The GECAM light curve could be found here:
https://twikinew.ihep.ac.cn/pubgecam/Sandbox/GRB/GECAMB_GRB241026A.png

We note that these results are 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).