GX Cas possible superoutburst The long-period (long Porb) SU UMa-type dwarf nova, GX Cas, is undergoing a outburst. The known supercycle suggests that the current outburst may be a superoutburst (Nogami et al. 1998, PASJ 50, 411 predicts the next super- outburst around Nov. 10), or a normal one just preceding the expected superoutburst. Follow-up observations are encouraged in order to confirm the prediction. The latest superoutburst of GX Cas was reported in 1997 October (Takahashi), reaching mv=12.8. YYMMDD(UT) mag observer 981001.860 <152 (T. Kinnunen) 981002.769 <152 (T. Kinnunen) 981003.069 <152 (G. Poyner) 981003.790 <145 (T. Kinnunen) 981005.769 <141 (T. Kinnunen) 981006.760 137 (T. Kinnunen) Regards, Taichi Kato