{
  "circularId": 44760,
  "eventId": "GRB 260601A",
  "submittedHow": "web",
  "body": "A. Holzmann Airasca (UniTrento and INFN Bari) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:\n\n\"At 11:00:12.44 UT on 01 June 2026, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 260601A (trigger 802004417/260601458).\n\nThe on-ground calculated location, using the Fermi GBM trigger data,\nis RA = 15.06, Dec = 44.38 (J2000 degrees, equivalent to\nJ2000 1h 0m, +44d 22'), with a statistical uncertainty of 2.03 degrees.\n(radius, 1-sigma containment, statistical only; there is additionally a\nsystematic error which we have characterized as a mixture of two Gaussians,\none with a radius of 1.8 degrees (52% contribution) and one with a radius\nof 4.1 degrees (47% contribution) [A. Goldstein et al. 2020, ApJ, 895, 1]).\n\nThe angle from the Fermi LAT boresight is 30 degrees.\n\nThe GBM light curve consists of a single emission episode with a duration (T90)\nof about 0.8 s (50-300 keV). The time-averaged spectrum\nfrom T0-0.07 to T0+0.34 s is best fit by\na power law function with an exponential high-energy cutoff.\nThe power law index is -0.63 +/- 0.02 and the cutoff energy,\nparameterized as Epeak, is 960 +/- 30 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(2.08 +/- 0.06)E-06 erg/cm^2. The 64-ms peak photon flux measured\nstarting from T0+0.064 s in the 10-1000 keV band is 40 +/- 1 ph/s/cm^2.\n\nA Band function fits the spectrum equally well\nwith Epeak= 750 +/- 20 keV, alpha = -0.57 +/- 0.05 and beta = -2.0 +/- 0.2.\n\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog:\nhttps://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html\n\nFor Fermi GBM data and info, please visit the official Fermi GBM Support Page:\nhttps://fermi.gsfc.nasa.gov/ssc/data/access/gbm/\"",
  "subject": "GRB 260601A: Fermi GBM Observation",
  "format": "text/plain",
  "submitter": "A. Holzmann Airasca at University of Trento and INFN Bari <a.holzmannairasca@unitn.it>",
  "createdOn": 1780337636968
}