Nonthermal Motions and Atmospheric Heating of Cool Stars

Abstract The magnetic processes associated with the nonthermal broadening of optically thin emission lines appear to carry enough energy heat corona and accelerate solar wind. We investigate whether motions in cool stars exhibit same behavior as on Sun by analyzing archival stellar spectra taken Hubble Space Telescope, full-disk Solar Interface Region Imaging Spectrograph. determined velocities measuring excess formed atmosphere; chromosphere, transition region, corona. Assuming is caused presence Alfvén waves, we also wave densities. Our results show that a velocity ∼23 km s −1 Sun-as-a-star are very good agreement values obtained from spatially resolved observations. our sample shows correlation rotation, strength decreasing rotation rate. Finally, Sun-like varies atmospheric height or temperature lines, peaks at region temperatures. This points toward solar-like wave-driven heating atmospheres. However, peak lower some suggesting other such flaring events could dominate.