TITLE: GCN CIRCULAR NUMBER: 26549 SUBJECT: GRB 191221B: AGILE/MCAL observations DATE: 19/12/22 09:23:58 GMT FROM: Francesco Longo at U of Trieste,INFN Trieste F. Longo (UniTS and INFN Trieste), M. Pilia (INAF/OA-Cagliari), F. Verrecchia (SSDC, and INAF/OAR) , A. Ursi (INAF/IAPS), 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 (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), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team: The AGILE Mini-CALorimeter (MCAL) detected the long GRB191221B at T0 = 2019-12-21 20:39:11.42 (+/- 0.01 s) already detected by Swift (Laha et al., 2019; GCN #26534). In the MCAL energy range (0.4-100 MeV), the burst lasted about ~15 s and released a total number of ~12000 counts over a background rate of 650 Hz. The light curve shows several peaks and can be found at http://www.agilescienceapp.it/notices/GRB_065726_504045551.415264.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.