TITLE: GCN CIRCULAR NUMBER: 26548 SUBJECT: LIGO/Virgo S191222n: upper limits from AGILE-GRID observations DATE: 19/12/22 08:17:30 GMT FROM: Francesco Longo at U of Trieste,INFN Trieste F. Longo (UniTS and INFN Trieste), M. Pilia (INAF/OA-Cagliari), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS), F. Lucarelli, C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna), report on behalf of the AGILE Team: In response to the LIGO-Virgo GW event S191222n at T0 = 2019-12-22 03:35:37.119 (UT) a preliminary analysis of the AGILE exposure at T0 shows that the Gamma-Ray Imaging Detector (GRID) exposure covered the 38% of the 90% c.l. localization region (LR) (19% of the LR was occulted by Earth). We performed an analysis of the GRID data in the energy range 50 MeV - 10 GeV on T0, where good exposure of the S191222n 90% c.l. LR was available. No candidate gamma-ray transient was detected. The following preliminary GRID values of 3-sigma upper limit (UL) are obtained: from 7.8e-07 to 4e-06 erg cm^-2 s^-1, with exposure of about 38% of the LR over the time interval ( T0 -2s ; T0 + 2s ); from 3.2e-07 to 1.6e-06 erg cm^-2 s^-1, with exposure of about 38% of the LR over the time interval ( T0s ; T0 + 10s ); from 3.4e-08 to 3.5e-06 erg cm^-2 s^-1, with exposure of about 42% of the LR over the time interval ( T0s ; T0 + 100s ); These measurements were obtained with AGILE observing a large portion of the sky in spinning mode. Additional analysis of AGILE data is in progress.