V521 Peg superoutburst YYYYMMDD(UT) mag observer 20180715.694 <153 (Hiroyuki Maehara) 20180715.7587 <132c (Yutaka Maeda) 20180716.7111 <134c (Yutaka Maeda) 20180717.9965 <139 (Eddy Muyllaert) 20180718.9931 <139 (Eddy Muyllaert) 20180719.9889 120 (Eddy Muyllaert)