TITLE: GCN CIRCULAR NUMBER: 10966 SUBJECT: GRB 100722A: Fermi GBM detection DATE: 10/07/23 08:12:08 GMT FROM: Elisabetta Bissaldi at MPE Elisabetta Bissaldi (MPE) reports on behalf of the Fermi GBM Team: "At 02:18:37.24 UT on 22 July 2010, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 100722A (trigger 301457919 / 100722096). The on-ground calculated location, using the GBM trigger data, is RA = 238.8, DEC = -15.6 (J2000 degrees, equivalent to 15h 55m, -15d 36), with an uncertainty of 1.1 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The Fermi Observatory executed a maneuver following this trigger and tracked the burst location for the next 5 hours, subject to Earth-angle constraints. The angle from the Fermi LAT boresight is 33 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of several peaks with a duration (T90) of 6.6 +/- 0.2 s (50-300 keV). The time-averaged spectrum from T0 to T0+6.7 s is best fit by a Band function with Epeak = 68.1 (-3.5/+3.4) keV, alpha = -1.01 (-0.06/+0.07), beta = -2.54 (-0.10/+0.08) (Castor C-STAT 627 for 479 d.o.f.). The event fluence (8-1000 keV) in this time interval is (9.5 +/- 0.09) erg/cm^2. The 1-sec peak photon flux measured starting from T0 in the 8-1000 keV band is 26.9 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."