YZ Cnc superoutburst following precursor? YYYYMMDD(UT) mag observer 20191215.6775 <150c (Yutaka Maeda) 20191220.094 126 (Gary Poyner) 20191220.6948 128cG (Yutaka Maeda) 20191220.994 128 (Gary Poyner) 20191221.0097 129 (Eddy Muyllaert) 20191222.6734 110cG (Yutaka Maeda) 20191223.7558 112cG (Yutaka Maeda)