TITLE: GCN CIRCULAR NUMBER: 10004 SUBJECT: GRB 090910: SuperAGILE Localization of a Long GRB DATE: 09/10/10 05:24:39 GMT FROM: Marco Feroci at IASF/INAF I. Donnarumma, Y. Evangelista, E. Del Monte, M. Feroci, F. Lazzarotto, L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda (INAF/IASF Rome), A. Giuliani, A. Chen, S. Mereghetti, F. Perotti, P. Caraveo (INAF/IASF Milan), A. Pellizzoni, M. Pilia (INAF/OA Cagliari), S. Vercellone (INAF/IASF Palermo), A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi, M. Galli, (INAF/IASF Bologna), M. Tavani, G. Pucella, F. D'Ammando, E. Striani, V. Vittorini, A. Argan, A. Trois, G. Piano, S. Sabatini (INAF/IASF Rome), G. Barbiellini, F. Longo, E. Moretti (INFN Trieste), P. Picozza, A. Morselli (INFN Roma-2), M. Prest, E. Vallazza (Universita` dell'Insubria), P. Lipari, D. Zanello (INFN Roma-1), and P. Giommi, C. Pittori, P. Santolamazza, F. Verrecchia (ASDC) and L. Salotti (ASI), on behalf of the AGILE Team, report: "SuperAGILE detected a long gamma ray burst on 10 October 2009, at 02:43:09 UT. The event had a duration of about 10 s in the 17-60 keV energy range, with a highly structured shape. Assuming a Crab-like energy spectrum, the peak flux on 1-s timescale was about 6.2E-07 erg/cm2/s. The burst position was reconstructed as (RA, Dec) (298.669, -22.538) deg, which is: RA(J2000) = 19h 54m 40.51s Dec(J2000) = -22d 32' 17.36" with an uncertainty of 3' radius. The given uncertainty accounts for both the statistical and systematic errors. An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress."