GZ Cnc superoutburst YYYYMMDD(UT) mag observer 20191122.732 139 (Rod Stubbings) 20191122.7807 139cG (Yutaka Maeda) 20191123.721 140 (Rod Stubbings) 20191129.7895 125cG (Yutaka Maeda) 20191203.8087 130cG (Yutaka Maeda)