V551 Sgr superoutburst SU UMa-type. YYYYMMDD(UT) mag observer 20150319.799 <150 (Andrew Pearce) 20150325.800 <150 (Andrew Pearce) 20150401.832 <152 (Andrew Pearce) 20150410.603 144 (Rod Stubbings) 20150412.537 145 (Rod Stubbings) 20150412.799 142 (Andrew Pearce)