TITLE: GCN CIRCULAR NUMBER: 21660 SUBJECT: LIGO/Virgo G298936: AGILE MCAL observations DATE: 17/08/23 16:01:43 GMT FROM: Francesco Verrecchia at ASDC, INAF-OAR M. Cardillo (INAF/IAPS), F. Verrecchia (SSDC and INAF/OAR), A. Bulgarelli (INAF/IASF-Bo), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), C. Pittori (SSDC and INAF/OAR), M. Pilia (INAF/OA-Cagliari), G. Piano (INAF/IAPS), A. Ursi(INAF/IAPS), I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN Trieste), G. Minervini, A. Argan, Y. Evangelista (INAF/IAPS), F. Lucarelli (SSDC and INAF/OAR), N. Parmiggiani, A. Zoli, V. Fioretti, F. Fuschino (INAF/IASF-Bo), A. Trois (INAF/OA-Cagliari) M. Marisaldi (INAF/IASF-Bo and Bergen University), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team: In response to the LIGO/Virgo GW event G298936 (T0 = 2017-08-23 13:13:58.518 UTC; GCN #21656), analysis of AGILE data shows that the satellite at T0 was in the South Atlantic Anomaly (SAA). Scientific telemetry was inhibited during the time interval (T0 -300 s; T0 + 500 s). At the moment of data acquisition obtained near the time interval defined above we obtained preliminary 3-sigma fluence upper limits (UL) for a 1 s integration time at different celestial positions within the G298936 90% c.l. localization region, from a minimum of 5.1e-7 erg cm^-2 to a maximum of 7.8e-7 erg cm^-2 (assuming as spectral model a power law with photon index 1.4). The AGILE-MCAL detector has a full solid angle acceptance, and is operational in the range 0.4 - 100 MeV. The MCAL current trigger rate is on average ~ 0.15 every 20 sec. Additional analysis of AGILE data is in progress.