GCN Circular 45495
Subject
GRB 260829A: SVOM/GRM observation
Event
Date
2026-09-02T10:51:42Z (15 hours ago)
From
Xinghao Luo at IHEP <2952704891@qq.com>
Via
Web form
SVOM/GRM team: Xing-Hao Luo, Yue Wang, Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP)
SVOM/ECLAIRs team: Stéphane Schanne (CEA)
Report on behalf of the SVOM team:
SVOM/GRM was triggered in-flight by GRB 260829A at 2026-08-29T06:08:29.000 (T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #45464) and GECAM-B (Xue-Yuan Zao et. al., GCN #45470).
With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of muplti-pulses with a T90 of 28 +3/-5 s in the 15-5000 keV band.
The SVOM/GRM light curve can be found here:
https://www.bursthub.cn/gcn/2026/svgrb260829A.png
In addition, the position of this burst, as determined by Fermi/GBM (RA = 242.3, Dec = -34.6, with a statistical uncertainty of 1.0 degrees, GCN #45464), is located at about 134 degrees from the SVOM optical axis, which is outside the ECLAIRs field of view.
With this localization, the time-averaged spectrum from T0-25 to T0+13 s is best fitted by a power law function. The power law index is -2.11 +0.07/-0.08. The event fluence (10-1000 keV) in this time interval is (6.197 +0.467/−0.406)E-05 erg/cm^2.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS.
The SVOM/GRM point of contact for this burst is: Xing-Hao Luo (IHEP) (luoxh@ihep.ac.cn)