TITLE: GCN CIRCULAR NUMBER: 35295 SUBJECT: GRB 231205B: AGILE detection DATE: 23/12/06 21:37:52 GMT FROM: Claudio Casentini at INAF-IAPS C. Casentini (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, Y. Evangelista, L. Foffano, G. Piano (INAF/IAPS), L. Baroncelli, A. Bulgarelli, A. Ciabattoni, A. Di Piano, V. Fioretti (INAF/OAS-Bologna), G. Panebianco (Univ. Bologna - INAF/OAS Bologna), N. Parmiggiani (INAF/OAS-Bologna), F. Lucarelli (SSDC, and INAF/OAR), P.W. Cattaneo (INFN Pavia), F. Longo (Univ. Trieste, and INFN Trieste), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), A. Ursi (ASI and INAF/IAPS), I. Donnarumma, E. Menegoni (ASI), A. Giuliani (INAF/IASF-Mi), F. Cutrona (Univ. Milano Bicocca) and P. Tempesta (TeleSpazio) report on behalf of the AGILE Team: The AGILE satellite detected the GRB 231205B at T0 = 2023-12-05 16:43:59 s (UTC), reported by Swift (GCNs #35269, #35275, #35291) and GECAM-B (GCN #35279). The burst is clearly visible in the AGILE scientific ratemeters of the MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV) detectors. The event lasted about 18 s and it released a total number of 11057 counts in the MCAL detector (above a background rate of 539 Hz) and 54466 counts in the AC-Top detector (above a background rate of 2889 Hz). In the scientific ratemeters of the AC-Top detector is visible a GRB precursor, centered around -25 s to the Swift T0 and lasting 10 seconds. The AGILE ratemeters light curves can be found at: http://www.agilescienceapp.it/notices/GRB231205B_AGILE_RM_ND.png Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.