{
  "bibcode": "2015GCN.17561....1R",
  "body": "O.J Roberts (UCD) and M. Stanbro (UAH) report on behalf\nof the Fermi GBM Team:\n\n\"At 22:59:50.66 UT on the 9th of March 2015, the Fermi\nGamma-Ray Burst Monitor triggered and located\nGRB 150309A (trigger 447634793/150309958), the second\nepisode of which was also detected by Swift\n(Cummings et al. 2015, GCN 17553). The GBM on-ground\nlocation is consistent with the Swift position.\n\nThe angle from the Fermi LAT boresight is 60 degrees.\n\nThe Swift trigger is observed in the GBM light curve at\nT0+200 s as a very soft, weak event with a duration of\nabout 60 s. The immediate light curve at the GBM trigger\ntime consists of a bright, main peak of unresolved emission\nepisodes, with a duration (T90) of about 52 s (50-300 keV).\nThe time-averaged spectrum from T0+0.0 s to T0+52.6 s is\nbest fit by a Band function with Epeak= 165 +/- 4 keV,\nalpha = -0.59 +/- 0.02 and beta = -2.59 +/- 0.10.\n\nThe event fluence (10-1000 keV) in this time interval is\n(3.9 +/- 0.1)E-05 erg/cm^2. The 1-sec peak photon flux\nmeasured starting from T0+17.5 s in the 10-1000 keV band\nis 15.2 +/- 0.3 ph/s/cm^2.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog.\"",
  "circularId": 17561,
  "createdOn": 1426000426000,
  "email": "oliver.roberts@ucd.ie",
  "subject": "GRB 150309A: Fermi GBM detection",
  "submitter": "Oliver Roberts at UCD/Fermi  <oliver.roberts@ucd.ie>",
  "eventId": "GRB 150309A"
}