TITLE: GCN CIRCULAR NUMBER: 26208 SUBJECT: LIGO/Virgo S191109d: upper limits from AGILE-GRID observations mailed-by: DATE: 19/11/09 06:57:35 GMT FROM: Carlotta Pittori at ASI SSDC, INAF-OAR V. Fioretti (INAF/OAS-Bologna), C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS), F. Lucarelli, F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, N. Parmiggiani (INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), F. Longo (Univ. Trieste, and INFN Trieste), report on behalf of the AGILE Team: In response to the LIGO-Virgo GW event S191109d at T0 = 2019-11-09 01:07:17.221 UTC a preliminary analysis of the AGILE exposure at T0 shows that the Gamma-Ray Imaging Detector (GRID) exposure covered about 25% of the 90% c.l. localization region (LR) (0% of 90% c.l. localization region (LR) is 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 S191109d 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 7.77e-07 to 8.79e-06 erg cm^-2 s^-1, with exposure of about 26% of the LR over the time interval ( T0 -2s ; T0 + 2s ); from 6.16e-07 to 8.61e-06 erg cm^-2 s^-1, with exposure of about 25% of the LR over the time interval ( T0s ; T0 + 5s ); from 3.06e-07 to 7.69e-06 erg cm^-2 s^-1, with exposure of about 25% of the LR over the time interval ( T0s ; T0 + 10s ); from 3.78e-08 to 7.69e-06 erg cm^-2 s^-1, with exposure of about 25% 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.