SDSS J225831.18-094931.7 possible superoutburst YYYYMMDD(UT) mag observer 20210607.7637 <139c (Yutaka Maeda) 20210609.7811 <137c (Yutaka Maeda) 20210613.2953 15.56C (Masao Funada) 20210619.7974 122c (Yutaka Maeda)