SIMBAD references

Using available observational data we have estimated the total radiative output from the chromospheric/coronal plasma as a result of magnetic heating for several F, G, K & M dwarfs. When tabulated as a function of the bolometric flux, a clear 'levelling-off/saturation' exists for the faster rotators as found previously when using single spectral lines. However, using recent chromospheric radiative transfer model calculations it is shown that this 'saturation' can be due to a significantly larger fraction of the losses being radiated by hydrogen in the ultraviolet/optical/infrared continuum regions. The implication being that these ultra-fast rotators have a high density chromosphere, plus a high temperature minimum, although additional chromospheric model calculations are required which include better molecular line opacities plus and an extension of the models for stars with higher effective temperatures.