Subject

Stars -- Spectra books

2 free books about stars -- spectra, free to read online. Chapter 1 of any book is free, no account needed.

Stellar atmospheres: A contribution to the observational study of high temperature in the reversing layers of stars

Cecilia Payne-Gaposchkin

On the distribution of intensity in stellar absorption lines

Payne-Gaposchkin, Cecilia; Shapley, Harlow