{
  "subject": "GRB 130504B: Fermi GBM detection",
  "eventId": "GRB 130504B",
  "bibcode": "2013GCN.14560....1V",
  "createdOn": 1367696950000,
  "circularId": 14560,
  "submitter": "Andreas von Kienlin at MPE  <azk@mpe.mpg.de>",
  "email": "azk@mpe.mpg.de",
  "body": "A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:\n\n\"At 07:32:03.39 UT on 04 May 2013, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 130504B (trigger 389345526/ 130504314).\n\nThe on-ground calculated location, using the GBM trigger\ndata, is RA = 353.5, DEC = -5.6 (J2000 degrees, equivalent to 23 h 34 m, -05\nd 34'),\nwith an uncertainty of 1 degree (radius, 1-sigma containment, statistical\nonly; \nthere is additionally a systematic error which is currently estimated to be\n2 to 3 degrees).\n\nThe angle from the Fermi LAT boresight is 57 degrees. Moreover, this \nburst was bright enough to result in a Fermi spacecraft autonomous \nrapid repoint (ARR) maneuver. \n\nThis burst was also independently detected by INTEGRAL SPI-ACS.\n\nThe GBM light curve consists of a single spike with a duration (T90) \nof about 0.4 s (50-300 keV). The time-averaged spectrum from T0-0.064 s \nto T0+0.448 s is best fit by a power law function with an exponential\nhigh-energy cutoff.  The power law index is -0.42 +/- 0.04  and the \ncutoff energy, parameterized as Epeak, is 1300 (+80/-70)keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(6.01 +/- 0.14)E-06 erg/cm^2. The 0.064-sec peak photon flux measured\nstarting from T0+0.32 s in the 10-1000 keV band\nis 40 +/- 2 ph/s/cm^2.\n\nA Band function fits the spectrum equally well with \nEpeak= 1300 +/-80 keV, alpha = -0.42 +/-0.04 \nand beta = -3.4 (+0.4/-0.9).\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog.\""
}