Opacity in the upper atmospheres of active stars - II. AD Leonis

摘要: We present FUV and UV spectroscopic observations of AD Leonis, with the aim investigating opacity effects in transition regions late-type stars. The $\ion{C}{iii}$ lines FUSE  spectra show significant during both quiescent flaring states up to 30% expected flux being lost latter. Other  emission lines tested for include those of $\ion{O}{vi}$, while $\ion{C}{iv}$, $\ion{Si}{iv}$ $\ion{N}{v}$ transitions observed stis are also investigated. These only reveal modest amounts losses 20%. Optical depths have been calculated homogeneous inhomogeneous geometries, giving path lengths ≈ 20–60 km 10–30 km, respectively, under conditions. However derived 2–3 times larger. values excellent agreement estimates small-scale structure solar region, previously several other active