TITLE: GCN CIRCULAR NUMBER: 45369 SUBJECT: GRB 260808A: SVOM/GRM observation DATE: 26/08/13 03:20:24 GMT FROM: Xinghao Luo at IHEP <2952704891@qq.com> SVOM/GRM team: Xing-Hao Luo, Chen-Wei Wang, Yue Wang, Jin-Ye Luo, Wen-Jun Tan, Yue Huang, Shi-Jie Zheng, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Marius Brunet (IRAP) Report on behalf of the SVOM team: SVOM/GRM observed GRB 260808A at 2026-08-08T02:51:45.500 UTC (T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #45313), NuSTAR (G. Waratkar et.al., GCN#45327) , CGBM (M.L. Cherry et.al., GCN#45347) and GECAM-B (Xing-Hao Luo et.al., GCN#45356). Unfortunately, ECLAIRs was not collecting data at the time of the burst. With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multiple pulses with a T90 of 21 +/-2 s in the 15-5000 keV band. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//gcn/2026/svgrb260808A.png In addition, the position of this burst, as determined by Fermi/GBM (RA=341.8 , DEC=14.1, with a statistical uncertainty of 2.2 degrees, Fermi GBM team, GCN #45313), is located at about 21 degrees from the SVOM optical axis, which is inside the ECLAIRs field of view. With this localization, the time-averaged spectrum from T0-5.5 to T0+20.5 s is best fitted by a power law function with an exponential high-energy cutoff. The power law index is -1.16 +0.11/-0.10 and the cutoff energy, parameterized as Epeak, is 194 +45/-30 keV. The event fluence (10-1000keV) in this time interval is (7.74 +0.68/-0.61)E-06 erg/cm^2. The 'Amati' relation diagram of GRB 260808A is shown at: https://www.bursthub.cn//gcn/2026/svgrb260808A_amati.png 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 point of contact for this burst is: Xing-Hao Luo (luoxh@ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/45369. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...