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.