On the Distribution of Intensity in Stellar Absorption Lines

A scientific publication written in the early 20th century. This work focuses on the quantitative analysis of the intensity and contours of absorption lines observed in the spectra of various stars, utilizing observational data and new measurement techniques. The document is technical in nature and is intended for readers with a background in astrophysics or astronomy, particularly those interested in stellar atmospheres and spectral analysis. The opening of this publication introduces the significance of studying stellar absorption lines for understanding atomic structure and star atmospheres, while noting a gap between theory and quantitative observation. The authors then outline their methodology: employing the Harvard Observatory's 16-inch refractor with objective prisms and specialized apertures to record spectra of eleven stars across different spectral types. They detail the use of a microphotometer to analyze the spectra and describe procedures to ensure accuracy, such as controlling for focus, stray light, and measurement consistency. Tables and figures present sample data and summarize results, highlighting key findings such as the relationship between a star's brightness and the depth of its absorption lines, and noting that even the deepest lines do not absorb all background light.