{
  "bibcode": "2009GCN..9366....1V",
  "body": "A. von Kienlin (MPE) and Sheila McBreen (UCD/MPE) \nreport on behalf of the Fermi GBM Team: \n\n\"At 05:10:05.72 UT on 09 May 2009, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 090509 (trigger 263538607 / 090509215)\nwhich was also detected by the SWIFT-BAT (Grupe et al. 2008, GCN 9325; \nKrimm et al., GCN 9349). The GBM on-ground location is consistent \nwith the Swift position.\n\nThe angle from the Fermi LAT boresight is 75 degrees.\n\nThe GBM light curve consists of two widely separated multi-peaked \nemission periods with a duration (T90) of about 295 s (8-1000 keV). \nThe time-averaged spectrum of the first emission complex from \nT0-3.072 to T0+24.576  s is well fit by a power law function with \nan exponential high energy cutoff.  The power law index is -0.90 +/- 0.16 \nand the cutoff energy, parameterized as Epeak, is 343 +/- 93 keV \n(chi squared 375 for 360 d.o.f.). \nThe time-averaged spectrum of the second emission complex from \nT0+239.619 s to T0+288.772 s is best fit by a simple power \nlaw function with index -1.55 +/- 0.07 (chi squared 328 for 361 d.o.f.).\n\nThe summed event fluence (8-1000 keV) of both time intervals is \n(8.4 +/- 0.4)E-06 erg/cm^2. The 1-sec peak photon flux measured \nstarting from T0+18.432 s in the 8-1000 keV band \nis 3.1 +/- 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": 9366,
  "createdOn": 1242401589000,
  "email": "azk@mpe.mpg.de",
  "subject": "GRB 090509: Fermi GBM observation",
  "submitter": "Andreas von Kienlin at MPE  <azk@mpe.mpg.de>",
  "eventId": "GRB 090509"
}