High resolution IUE observations of the flare star AD Leonis : implications for the MG II Wilson-Bappu effect.
Pettersen, B. R.; Ambruster, C. W.; Sundland, S. R.
United States, Norway
Abstract
The first high resolution IUE observations of the classical M dwarf flare star, AD Leonis is reported. For the Mg II h and k emission lines (2795 and 2803 A), no variation in the line strength, width, or flux is found in four spectra spanning 24 hr. The lines are broader in AD Leo than in AT Microscopii and AU Microscopii, the only other M dwarfs to have been observed in high dispersion by IUE. The line widths appear to support a 5 mag linear extension of the Mg II Wilson-Bappu relation, recently calibrated for brighter stars, to low luminosity dwarfs.