Likely superoutburst of TT Boo The SU UMa-type dwarf nova TT Boo is undergoing a bright (likely super-) outburst as indicated by the following observations. The latest superoutburst of TT Boo was observed in 1998 February. YYMMDD(UT) mag observer 980821.882 <148 (G. Poyner) 980822.153 <154 (G. Hanson) 980822.271 <139 (L. E. Shaw) 980822.876 <148 (G. Poyner) 980823.160 <153 (G. Hanson) 980824.819 <137 (T. Kinnunen) 980824.887 <148 (G. Poyner) 980825.869 131 (M. Verdenet) 980825.890 128 (M. Verdenet) 980825.899 130 (J. Gunther) 980825.910 126 (M. Verdenet) Regards, Taichi Kato