GCN Circular 44349
Subject
GRB 260417A: SVOM/GRM observation
Event
Date
2026-04-19T16:33:14Z (21 days ago)
From
zhangjinpeng@ihep.ac.cn
Via
Web form
SVOM/GRM team: Jin-Peng Zhang, Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP)
SVOM/ECLAIRs team: Sebastien Guillot (IRAP)
Report on behalf of the SVOM team:
SVOM/GRM detected GRB 260417A at 2026-04-17T00:10:11.500 (T0), which is also detected by Fermi/GBM (Fermi GBM Team, GCN #44317), AstroSat CZTI (S. Salunke et al., GCN #44330) and possibly by EP (K. R. Ni et al., GCN #44337).
With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst mainly consists of a pulse with a T90 of 38 +15/-10 s in the 15-5000 keV band.
The SVOM/GRM light curve can be found here:
https://www.bursthub.cn//admin/static/svgrb260417A.png
In addition, the position of this burst, according to Fermi/GBM localization (RA = 252.0, Dec = -19.8, error(stat) = 3.4, Fermi GBM Team, GCN #44317), is located at about 90.3 degrees from the SVOM optical axis, which is outside the ECLAIRs field of view.
With this localization, the time-averaged spectrum from T0-20 to T0+20 s is fitted by a power law function. The power law index is -1.77 +0.09/-0.09. The event fluence (10-1000 keV) in this time interval is (9.1 +1.0/-1.1)E-06 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: Jin-Peng Zhang (IHEP) (zhangjinpeng@ihep.ac.cn)