MASTER OT J172758.09+380021.5 likely superoutburst YYYYMMDD(UT) mag observer 20170602.758 <163c (Mitsutaka Hiraga) 20170609.733 <158c (Mitsutaka Hiraga) 20170615.556 145c (Mitsutaka Hiraga) and also MASTER_OT_J172758.09+380021.5 20170613.320 14.80V ASN