MASTER OT J055845.55+391533.4 superoutburst continues YYYYMMDD(UT) mag observer 20190331.4975 142cG (Yutaka Maeda) 20190401.5291 145c (Yutaka Maeda) 20190402.5113 143cG (Yutaka Maeda) 20190403.4971 145cG (Yutaka Maeda) 20190405.5049 151cG (Yutaka Maeda) 20190412.4772 152c (Yutaka Maeda)