Quantitative astronomical spectroscopy in the post Saha equation period

Abstract

Several new questions of quantitatively estimating physical conditions on

astronomical bodies had opened up after formulation of Saha Ionization

Equation. The article first reviews the step by step progress in the

establishment of a stellar temperature scale. The second point reviewed is

the efforts by many groups for determining elemental abundances and

finding the solution to the Hydrogen problem. Finally some current efforts

to read the magnetic field characteristics from polarization profiles of Zeeman

affected spectral lines have been described.