TITLE: GCN CIRCULAR NUMBER: 28714 SUBJECT: GRB 201020B: AGILE detection DATE: 20/10/21 08:43:31 GMT FROM: Alessandro Ursi at INAF/IAPS A. Ursi (INAF/IAPS), M. Pilia (INAF/OA-Cagliari), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli, C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team: The AGILE Mini-CALorimeter (MCAL) detected GRB 201020B at T0 = 2020-10-20 17:34:03.78 +/- 0.01 s (UTC), reported by Fermi/GBM (GCNs #28702 and #28710). The event lasted about 5 s and released a total number of 3250 counts in the detector (in the 0.4-100 MeV energy range), above an average background rate of 550 Hz. The MCAL light curve can be found at http://www.agilescienceapp.it/notices/GRB_069336_525794310.907011.png . The time-integrated spectrum of the burst can be fitted in the energy range 0.4-20 MeV with a single power-law with ph.ind. = -2.78 -0.03/+0.04, resulting in a reduced chi-squared of 1.05 (89 d.o.f.) and a fluence of 4.56e-06 ergs/cm^2 (90% confidence level), in the same energy range. The burst is clearly visible in the AGILE scientific ratemeters of the SuperAGILE (SA; 20-60 keV), MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV) detectors. The event lasted ~27 s and released a total number of 5856 counts in the SA detector (above a background rate of 80 Hz); it lasted ~17.5 s and released a total number of 66750 counts in the AC detector (above a background rate of 3670 Hz); it lasted ~5 s and released a total number of 7506 counts in the MCAL detector (above a background rate of 1260 Hz). The AGILE ratemeter light curves can be found at http://www.agilescienceapp.it/notices/GRB_201020B_AGILE_RM.png . The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the energy range 0.4-100 MeV. 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.