MKN421 active state update YYYYMMDD(UT) mag observer 20010224.837 126 (E. Muyllaert) 20010225.530 127 (T. Watanabe) 20010225.551 128 (T. Watanabe) 20010225.931 126 (E. Muyllaert) 20010225.949 124 (J. Ripero) 20010227.810 128 (P. A. Dubovsky) 20010227.919 127 (M. Reszelski) 20010228.294 126 (M. Simonsen) 20010301.308 128 (M. Simonsen) 20010301.874 128 (G. Poyner) 20010301.937 123 (H. McGee) 20010301.972 126 (M. Reszelski) 20010302.910 128 (G. Poyner) 20010303.017 125 (M. Reszelski) 20010304.956 129 (G. Poyner) 20010305.878 129 (G. Poyner) 20010307.110 128 (M. Reszelski)