The coronal FeXXI lambda 1354.094 line in AB Doradus

The active late-type star AB Doradus was observed in February 1996 with the Goddard High Resolution Spectrograph of the Hubble Space Telescope using t he low resolution G140L grating. The observations covered one half of the s tar's rotation cycle (P = 0.514 d) with 11.5 min time resolution. The stron g coronal FeXXI lambda 1354.094 line formed at 10(7) K was analysed and its emission measure (EM) derived. This EM is much higher than that derived fr om recent XMM-Newton observations (Gudel et al. 2001), and earlier EXOSAT ( Collier Cameron et al. 1988) and ASCA/EUVE (Mewe et al. 1996) data, as well , requiring a variability by a factor of 5. The physical reason for the var iability remains unknown, since (outside flares) the observed broad band va riability of AB Dor is much smaller.