{
  "createdOn": 1781706442375,
  "submittedHow": "web",
  "format": "text/plain",
  "submitter": "guohx@ihep.ac.cn",
  "subject": "GRB 260616A: GECAM-B observation",
  "circularId": 44964,
  "body": "Hao-Xuan Guo, Zheng-Hang Yu, Chen-Wei Wang, Chao Zheng, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:\n\nGECAM-B was triggered in-flight by GRB 260616A, at 2026-06-16T03:21:40.040 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi/GBM team, GCN #44948), BALROG (T. Preis et al., GCN #44949), Fermi/LAT (S. Lopez et al., GCN #44960).\n\nAccording to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 117 +/-3 s.\n\nThe GECAM-B light curve can be found here:\nhttps://www.bursthub.cn//admin/static/gecambgrb260616A.png\n\nUsing the localization reported by Fermi/LAT (R.A. = 93.53 deg, Dec = -32.07 deg, Err = 0.54 deg, GCN #44960) , the time-averaged spectrum from T0-77.5 s to T0+133.5 s is best fitted by a power law function with an exponential high-energy cutoff. The power law index is -1.35 +0.08/-0.07 and the cutoff energy, parameterized as Epeak, is 679 +141/-121 keV. The event fluence (10-1000 keV) in this time interval is (2.02 +0.05/-0.06)E-04 erg/cm^2.\n\nThe 'Amati' relation diagram of GRB 260616A is shown at:\nhttps://www.bursthub.cn//admin/static/gecambgrb260616A_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).",
  "bibcode": "2026GCN.44964....1G",
  "eventId": "GRB 260616A"
}