TITLE: GCN CIRCULAR NUMBER: 16450 SUBJECT: GRB 140623A / iPTF14cyb: Fermi GBM detection DATE: 14/06/24 14:58:54 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: "At 05:22:06.60 UT on 23 June 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140623A (trigger 425193729 / 140623224), which was observed by the intermediate Palomar Transient Factory beginning 11 minutes after trigger time, and was reported in GCN 16425 (Bhalerao et al. 2014) as iPTF14cvb. The on-ground calculated location, using the GBM trigger data, is RA = 202.8, DEC = 75.8 (J2000 degrees, equivalent to 13h 31m, 75d 48'), with an uncertainty of 5.6 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight is 32 degrees. The GBM light curve shows a multiple-peak structure with a duration (T90) of about 110 s (50-300 keV). The time-averaged spectrum from T0-49.2 s to T0+73.7 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.46 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 350(+220/-100) keV The event fluence (10-1000 keV) in this time interval is (6.8 +/- 0.6)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0-3.65 s in the 10-1000 keV band is 1.9 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."