{
  "submittedHow": "web",
  "circularId": 41630,
  "body": "Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:\n\nGECAM-B was triggered in-flight by a bright long burst GRB 250830C at 2025-08-30T14:51:55.100 UTC (denoted as T0). According to the GECAM-B light curves in about 40-6000 keV, this burst mainly consists of a precursor followed by multiple pulses main emission with a duration (T90) of 23.6 +12.0/-8.4 s.\n\nThe GECAM-B light curve can be found here:\nhttps://www.bursthub.cn//admin/static/gecamgrb250830C.png\n\nGECAM-B localized this burst to the following position (J2000): \nRa: 240.1 deg \nDec: 40.5 deg\nErr: 1.1 deg (1-sigma, statistical only)\n\nThe time-averaged spectrum from T0-2 s to T0+40 s is best fitted by a power law function with an exponential high-energy cutoff. The power law index is -1.06 +0.23/-0.24 and the cutoff energy, parameterized as Epeak, is 255 +121/-46 keV. The event fluence (10-1000 keV) in this time interval is (2.41 +/-0.36)E-05 erg/cm^2. The 'Amati' relation diagram of GRB 250830C is shown at: \nhttps://www.bursthub.cn//admin/static/grb250830C_amati.png\n\nGravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission originally consists of two micro-satellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS).\n",
  "createdOn": 1756749003104,
  "bibcode": "2025GCN.41630....1W",
  "format": "text/plain",
  "subject": "GRB 250830C: GECAM-B detection",
  "eventId": "GRB 250830C",
  "submitter": "Chenwei Wang at IHEP <cwwang@ihep.ac.cn>"
}