{
  "circularId": 46111,
  "submitter": "Xinghao Luo at IHEP <2952704891@qq.com>",
  "format": "text/plain",
  "subject": "GRB 261024D: SVOM/GRM observation",
  "eventId": "GRB 261024D",
  "submittedHow": "web",
  "createdOn": 1793367023733,
  "body": "SVOM/GRM team: Xing-Hao Luo, Yue Wang, Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP)\n\nSVOM/ECLAIRs team: Oliver Godet (IRAP)\n\nReport on behalf of the SVOM team:\n\nSVOM/GRM was triggered in-flight by GRB 261024D (SVOM trigger reference: sb26102402) at 2026-10-24T21:33:06.000 (T0), which is also detected by AstroSat CZTI (A. Goyal et.al., GCN#46040), NuSTAR (G. Waratkar et.al., GCN#46051), Glowbug gamma-ray telescope (C. C. Cheung et.al., GCN#46053), GECAM-B (Xing-Hao Luo et.al., GCN#46061) and Insight-HXMT (Xing-Hao Luo et.al., GCN#46065).\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-value of 11.0 +2.5/-1.0 s in the 15-5000 keV band.\n\nThe SVOM/GRM light curve can be found here:\nhttps://www.bursthub.cn/gcn/2026/svgrb261024D.png\n\nIn addition, the position of this burst, as determined by GECAM-B (RA = 208.64 deg, Dec = 25.1 deg, with a statistical uncertainty of 5.46 degrees, Xing-Hao Luo et.al., GCN #46061), is located at about 155 degrees from the SVOM optical axis, which is outside the ECLAIRs field of view. However, ECLAIRs detected this burst by reflection onto the Earth atmosphere since the Earth fraction was 1 at the time of the burst.\n\nWith this localization, the time-averaged spectrum from T0-1.5 to T0+11 s is best fitted by a power law function with an exponential high energy cutoff. The power law index is -1.32 +0.17/-0.16 and the cutoff energy, parameterized as Epeak, is 131 +11/-10 keV. The event fluence (10-1000 keV) in this time interval is (2.22 +0.13/−0.12)E-05 erg/cm^2. \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/GRM point of contact for this burst is: Xing-Hao Luo (IHEP) (luoxh@ihep.ac.cn)\n",
  "eventType": [
    "GRB",
    "X-ray Transient"
  ]
}