TITLE: GCN CIRCULAR NUMBER: 9072 SUBJECT: GRB DATE: 09/04/01 15:51:31 GMT FROM: Ascension Camero-Arranz at NASA VP62/FECYT Subject: GRB 090331: Fermi GBM detection A. Camero-Arranz (NASA; FECYT) and C. Wilson-Hodge (NASA/MSFC), report on behalf of the Fermi GBM Team: "At 16:20:20.39 UT on 03 31 09, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 090331 ( trigger 260209222/ 090331681). The on- ground calculated location, using the Fermi GBM trigger data, is RA = 212.38, Dec = -0.51 (J2000 degrees, equivalent to J2000 14h 09m, -00d 31' ), with a statistical uncertainty of 6.7 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 40 degrees. Since the source is weak, the time-averaged spectrum is poorly constrained." Subject: GRB 090331: Fermi GBM detection A. Camero-Arranz (NASA; FECYT) and C. Wilson-Hodge (NASA/MSFC), report on behalf of the Fermi GBM Team: "At 16:20:20.39 UT on 03 31 09, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 090331 ( trigger 260209222/ 090331681). The on- ground calculated location, using the Fermi GBM trigger data, is RA = 212.38, Dec = -0.51 (J2000 degrees, equivalent to J2000 14h 09m, -00d 31' ), with a statistical uncertainty of 6.7 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 40 degrees. Since the source is weak, the time-averaged spectrum is poorly constrained."