The methodology of Paper III is applied to delineate the principal parameters affecting the characteristics of the self-reversed emission cores of Ca+ H and K, in order to clarify whether current discussions in terms only of are adequate. We find two additional factors to be significant-c and the Te gradient. The factor E provides an effect in the correct direction to interpret the Wilson-Bappu effect, but of too small a size, subject to a more complete treatment of the region outside the Doppler core. The effect of the T6 gradient seems more significant, particularly as a basis for interpreting the observed solar variations.
No takes yet. Share an insight, caveat, or question.
Jefferies et al. (1960) studied this question.