CRTS J063437.9+412047 superoutburst YYYYMMDD(UT) mag observer 20190202.4848 <161c (Yutaka Maeda) 20190204.6628 160c (Yutaka Maeda) 20190206.6328 160c (Yutaka Maeda) 20190207.6187 149c (Yutaka Maeda)