TITLE: GCN CIRCULAR NUMBER: 16447 SUBJECT: GRB 140621A: Fermi GBM detection DATE: 14/06/23 21:29:38 GMT FROM: George A. Younes at USRA/NASA/MSFC G. Younes (USRA/NASA-MSFC) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 19:50:10.89 UT on 21 June 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140621A (trigger 425073013/140621827, IPN triangulation: Golenetskii at al., GCN 16444), which was also detected by Konus-Wind (Golenetskii et al., GCN 16445), and INTEGRAL SPI-ACS. The angle from the Fermi LAT boresight, using the GBM on-ground calculated location, is 97 degrees. The GBM light curve consists of two prominent peaks with a duration (T90) of about 6.4 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+6.14 s is adequately fit by a Band function with Epeak = 298 +/- 24 keV, alpha = -0.3 +/- 0.1, and beta = -2.3 +/- 0.2 The event fluence (10-1000 keV) in this time interval is (1.13 +/- 0.03)E-05 erg/cm^2. The 1 second peak photon flux measured starting from T0-0.128 s in the 10-1000 keV band is 8.3 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."