GCN Circular 31175

A. Ursi (INAF/IAPS), C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS,
and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y.
Evangelista, L. Foffano, E. Menegoni, G. Piano (INAF/IAPS), F. Lucarelli,
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), M. Pilia, 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 a burst at T0 = 2021-12-06
19:51:10.80 +/- 0.01 s (UTC). The event lasted about 4.5 s and released a
total number of ~3374 counts in the detector (in the 0.4-100 MeV energy
range), above an average background rate of 599 Hz. The MCAL light curve
shows two main peaks and can be found at
http://www.agilescienceapp.it/notices/075998_GRB_MCAL_565905070.805285.png

The burst is also 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 about 5 s and
it released a total number of 853 counts in the SA detector (above a
background rate of 90 Hz), 8286 counts in the MCAL detector (above a
background rate of 1260 Hz), and 18890 counts in the AC detector (above a
background rate of 3600 Hz). The AGILE ratemeter light curves can be found
at http://www.agilescienceapp.it/notices/GRB211206A_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.