TT Boo superoutburst The SU UMa-type dwarf nova TT Boo is likely undergoing a superoutburst as indicated by the following observations. The latest superoutburst of TT Boo occurred in 1999 Jan. (mv=12.7, Kinnunen et al.) YYMMDD(UT) mag observer 990711.953 <148 (G. Poyner) 990711.956 <142 (H. McGee) 990712.094 <139 (J. McKenna) 990712.974 <148 (G. Poyner) 990713.969 <154 (G. Poyner) 990714.901 143 (J. Ripero) 990714.910 140: (J. Gunther) 990714.930 135: (H. McGee) 990715.912 132 (P. A. Dubovsky) 990715.915 129 (E. Muyllaert) 990715.940 127 (H. McGee) 990716.916 133: (P. A. Dubovsky)