TITLE: GCN CIRCULAR NUMBER: 26934 SUBJECT: LIGO/Virgo S200128d: upper limits from AGILE/GRID observations DATE: 20/01/29 14:22:55 GMT FROM: Francesco Verrecchia at SSDC,INAF-OAR F. Verrecchia (SSDC, and INAF/OAR), A. Ursi (INAF/IAPS), C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano (INAF/IAPS), F. Lucarelli, A. Bulgarelli, V. Fioretti, 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 S200128d at T0 = 2020-01-28 02:20:11.903 UTC a preliminary analysis of the AGILE data shows that no AGILE/MCAL and AGILE/GRID data were available at T0 due to a telemetry gap. We performed an analysis of the GRID data in the energy range 50 MeV - 10 GeV over time intervals before and after T0, where good exposure of the S200128d 90% c.l. LR was available. No candidate gamma-ray transient was detected. The following preliminary GRID value of 3-sigma upper limit (UL) is obtained: from 3.6e-08 to 3.4e-06 erg cm^-2 s^-1, with exposure of about 44% of the LR over the time interval ( T0 + 200 s ; T0 + 300 s ); These measurements were obtained with AGILE observing a large portion of the sky in spinning mode. Additional analysis of AGILE data is in progress.