1997A&A...325..249S

We present simultaneous soft X-ray and FUV observations of the rapidly rotating young star AB Doradus (HD 36705), obtained with the position sensitive proportional counter (PSPC) on board ROSAT and the FUV/EUV spectrometer on board ORFEUS. The X-ray data show that AB Dor was in a high state, possibly in a flare, during the FUV observations. The lines of CIII at 977Å and OVI at 1032 and 1038Å are clearly detected in the ORFEUS spectrum. The overall emission measure distribution of the combined FUV and X-ray data is steeply rising. The OVI 1032Å line is definitely broadened with respect to the instrumental line profile, however, the observed broadening does not exceed the photospheric vsin(i)-value. This strongly suggests that the observed OVI emission, formed at a characteristic temperature of ≃300000K, is produced almost exclusively relatively close to the star's surface, and not in an extended corotating emission region with scale sizes of a few stellar radii.