{
  "subject": "GRB 260208B: SVOM/GRM observation of a bright burst",
  "createdOn": 1770572427013,
  "submittedHow": "web",
  "eventId": "GRB 260208B",
  "format": "text/plain",
  "body": "SVOM/GRM team: Xing-Hao Luo, Wen-Jun Tan, Chen-Wei Wang, Zheng-Hang Yu, Yue Huang, Shi-Jie Zheng, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP)\n\nSVOM/ECLAIRs team: Hui Yang (IRAP)\n\nReport on behalf of the SVOM team:\n\nSVOM/GRM was triggered in-flight by GRB 260208B (SVOM trigger reference: sb26020804) at 2026-02-08T09:52:48.000 UTC (T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #43638) and Fermi/LAT (F. Longo et al., GCN #43647).\n\nWith the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multi-pulses with a T90 of 147 +1/-1 s in the 15-5000 keV band.\n\nThe SVOM/GRM light curve can be found here:\nhttps://www.bursthub.cn//admin/static/svgrb260208B.png\n\nIn addition, the position of this burst, as determined by Fermi/GBM (RA=99.9 , DEC=-13.1, Fermi GBM team, GCN #43638), is located at about 64 degrees form the SVOM optical axis, which is outside the ECLAIRs field of view, but this burst is still clearly detected by ECLAIRs through the shield.\n\nWith this localization, the time-averaged spectrum from T0-12 to T0+166 s is best fitted by a power law function with an exponential high-energy cutoff. The power law index is -1.01 +0.04/-0.04 and the cutoff energy parameterized as Epeak, is 830 +105/-89 keV. The event fluence (10-1000keV) in this time interval is (1.09 +0.024/-0.025)E-04 erg/cm^2. \n\nThe 1s peak spectrum, measured from T0+11 to T0+12 s, is also best fitted by a power law function with an exponential high-energy cutoff. The power law index is -0.81 +0.03/-0.03 and the cutoff energy, parameterized as Epeak, is 1520 +130/-120 keV. The flux (10-1000 keV) in this time interval is (1.011 + 0.019/-0.019)E-05 erg/cm^2/s.\n\nThe localization of GRB 260208B in the 'Amati' relation diagram is shown at: \nhttps://www.bursthub.cn//admin/static/svgrb260208B_amati.png\nThe localization of GRB 260208B in the 'Yonetoku' relation diagram is shown at: \nhttps://www.bursthub.cn//admin/static/svgrb260208B_yonetoku.png\n\nThe 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.\n\nThe SVOM point of contact for this burst is: Xing-Hao Luo (luoxh@ihep.ac.cn)\n\n",
  "circularId": 43650,
  "bibcode": "2026GCN.43650....1S",
  "submitter": "Chenwei Wang at IHEP <cwwang@ihep.ac.cn>"
}