POSSIBLE BINARY LENS ALERT. OGLE-1999-BUL-11 event light curve clearly deviates from a single microlensing fit. If it really is a microlensing event, it is quite likely a binary event. Follow-up observations are strongly encouraged. Field BUL_SC36 StarNo 336761 RA(J2000.0) 18:05:29.59 Dec(J2000.0) -27:59:14.4 Remarks "single" event fit parameters: Tmax 2451291.220 0.255 tau 13.706 0.976 Amax 3.956 0.281 Dmag 1.493 0.077 I0 18.541 0.011 Finding charts, light curve plots, photometric data (updated regularly) can be found in: http://vsnet.astrouw.edu.pl/~ftp/ogle/ogle2/ews/bul-11.html http://vsnet.astrouw.edu.pl/ogle/ogle2/ews/1999/bul-11.tar.gz regards, OGLE team.