TITLE: GCN CIRCULAR NUMBER: 9075 SUBJECT: GRB 090401B: AGILE refined analysis DATE: 09/04/01 17:52:03 GMT FROM: Sara Cutini at ASDC A.Giuliani (INAF/IASF Milan), S.Cutini, C. Pittori (ASDC) E. Moretti, F.Longo, G.Barbiellini, E.Vallazza (INFN Trieste), M. Marisaldi, A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Galli, (INAF/IASF Bologna), A. Chen, S. Mereghetti, F. Perotti, P. Caraveo (INAF/IASF Milan), E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci, L. Pacciani, P. Soffitta, E. Costa, F. Lazzarotto, I. Lapshov, M. Rapisarda(INAF/IASF Rome), A. Pellizzoni, M. Pilia (INAF/OA Cagliari), S. Vercellone (INAF/IASF Palermo), M. Tavani, G. Pucella, F. D'Ammando, V.Vittorini, A. Argan, A. Trois, G. Piano, S. Sabatini (INAF/IASF Rome), P. Picozza, A. Morselli (INFN Roma-2), M. Prest (Universita` dell'Insubria), P.Lipari, D. Zanello (INFN Roma-1), A.Rappoldi, P.Cattaneo (INFN Pavia) and P. Giommi, P. Santolamazza, F.Verrecchia (ASDC) and L. Salotti (ASI), on behalf of the AGILE Team, report: A more refined analysis of the AGILE-GRID (Gamma-Ray Imaging Detector) data of GRB 090401B (Moretti et al. GCN 9069) confirms the gamma-ray detection of the GRB at energies above 30 MeV with a statistical significance larger than 4 for a 10-second integration after trigger. Fluence estimate for a 10 second integration is 0.038+/-0.011 ph/cm2 (above 30 MeV). The GRB 090401B gamma-ray spectrum appears to be relatively hard. An estimate of fluence in the 500 keV - 10 MeV range, as derived from MCAL data, is (1.6 +/- 0.5)e-5 erg/cm2 in the same time interval. This message may be cited.