1989•NASA Technical Reports Server (NASA)Requires access
Magnetic structure in cool stars. XVI. Emissions from the outer atmospheres of M-type dwarfs
R. G. M. Rutten, Carolus J. Schrijver, Cornelis L. Zwaan, Douglas K. Duncan, Rolf Mewe
Open publisher page 4 citations
Abstract
Consideration is given to emission from the outer atmospheres of M-type dwarfs in several spectral lines originating from the chromosphere, the transition-region, and the soft X-ray emission from the corona. It is shown that M-type dwarfs systematically deviate from relations between flux densities in soft X-rays and chromospheric and transition-region emission lines. The quantitative relation between the equivalent width of H-alpha and the Ca II, H, and K emission index is determined. It is suggested that the emission in the Balmer spectrum may result from back heating by coronal soft X-rays.