MASTER OT J221811.12+654219.9 superoutburst YYYYMMDD(UT) mag observer 20210908.3480 19.897zr (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210908.5962 <163c (Yutaka Maeda) 20210909.6506 <166c (Yutaka Maeda) 20210910.1999 15.073zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210910.2206 15.005zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20210912.2642 14.551zg (Zwicky Transient Facility Lasair (Masci+ 2019))