TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3093 SUBJECT: GRB050223: No XMM-Newton OM detection of afterglow emission DATE: 05/03/15 19:35:46 GMT FROM: Alexander Blustin at MSSL-UCL A. Blustin (MSSL), G. Branduardi-Raymont (MSSL), A. Breeveld (MSSL), C. Brocksopp (MSSL), M. Cropper (MSSL), C. James (MSSL), N. Loaring (MSSL), K. Mason (MSSL), K. McGowan (MSSL), M. de Pasquale (MSSL), M. Page (MSSL), T. Poole (MSSL), G. Ramsay (MSSL), S. Rosen (MSSL), C. Saxton (MSSL), P. Schady (MSSL), K. Wu (MSSL), S. Zane (MSSL), H. Ziaeepour (MSSL) on behalf of the XMM-Newton Optical Monitor team The XMM-Newton Optical Monitor began observations of GRB050223 at 14:23:15 on 2005-02-23, about 11 hours after the initial Swift BAT trigger (Mitani et al, GCN 3055). We detect no source at the position of the XMM-Newton pn source (Gonzalez-Riestra et al, GCN 3060). The estimated limiting magnitudes (5-sigma) in each of the OM filters are as follows: Filter Lim_Mag Duration T_start B 21.22 4000 T+40449 UVW1 20.24 2500 T+60374 UVW1 20.49 4000 T+63181 UVM2 19.60 4000 T+67488 UVM2 19.56 4000 T+71795 UVW2 18.70 4000 T+76102 UVW2 18.67 4000 T+80409 UVW2 18.64 4000 T+84716 This message may be cited.