//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9904 SUBJECT: GRB 090910: Fermi GBM detection DATE: 09/09/11 19:32:46 GMT FROM: Vandiver Chaplin at UAH/Fermi-GBM V.Chaplin (UAH) reports on behalf of the Fermi GBM Team: "At 19:29:48.81 UT on 10 SEP 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090910 (trigger 274303790 / 090910812). The on-ground calculated location, using the GBM trigger data, is RA = 296.2, DEC = 72.3 (J2000 degrees, equivalent to 19h 44m, 72 d 18'), with an uncertainty of 1.0 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 107 degrees. The on-board GBM Flight Software localization for this event, as reported in the GCN notice, was consistent with a position near the Earth's limb. Furthermore, the trigger occurred as the spacecraft was at a high magnetic latitude. The resulting autonomous classification for the event was "Distant Particles", which is erroneous. The GBM light curve consists of three distinct pulses close in time from T0-5s to about T0+45s, with a smaller pulse visible in several detectors at about T0+70s. The duration (T90) of this event is approximately 62s (8-1000 keV). The time-averaged spectrum from T0-7.2 s to T0+44 s is best fit by a Band function with Epeak = 274.8 +/- 56.1 keV, alpha = -0.9 +/- 0.1, and beta = -2.0 +/- 0.2 (chi squared 397.41 for 360 d.o.f.). The event fluence (8-1000 keV) in this time interval is (9.2 +/- 0.7)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+2 s in the 8-1000 keV band is 2.3 +/- 0.6 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// 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." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10005 SUBJECT: SuperAGILE GRB is 091010 and not 090910 DATE: 09/10/10 05:42:54 GMT FROM: Marco Feroci at IASF/INAF Marco Feroci (INAF/IASF Rome) reports: I made a mistake in the name of the GRB, that is GRB 091010 instead of GRB 090910, as cited in the previous circular. The burst trigger time indicated in GCN #10004 was correct. I apologize for the confusion.