SDSS J100515.39+191108.0 superoutburst YYYYMMDD(UT) mag observer 20210430.556 <150 (Hiroyuki Maehara) 20210502.2480 18.599zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210518.4825 129cG (Yutaka Maeda) 20210522.4891 126cG (Yutaka Maeda)