RX J0640-24 superoutburst? YYYYMMDD(UT) mag observer 20010531.394 <128 (R. Stubbings) 20010607.676 114 (B. Monard) 20010608.682 115 (B. Monard) 20010609.705 115 (B. Monard) 20010610.366 120 (R. Stubbings) 20010610.680 115 (B. Monard)