On the Differences at Chromospheric Levels between RS Cvn-Type Binaries, Active and Quiet Chromosphere Single Stars, and Active and Quiet Regions in The Sun

Abstract

RS CVn-type systems exhibit many similarities to active regions on the Sun. In the last few years considerable progress has been made in quantifying the differences between the atmospheric properties of solar plages and quiet regions. These differences, as summarized in Linsky’s (1979) review, can be simply explained by additional nonradiative heating and include the following: (1) temperature enhancements in the photosphere, (2) heating of the temperature minimum and its displacement downward in mass column density, (3) enhanced radiative losses in the chromosphere and transition region (typically by a factor of 10), (4) steeper chromospheric temperature gradients, and (5) enhanced pressures and densities at the top of the chromosphere, throughout the transition region, and at the base of the corona (again typically by a factor of 10).