Philip C. Keenan

1908

• An atlas of spectra of the cooler stars
• Abundance effects in classification
• Studies of the emission lines in the spectrum of the solar chromosphere ..
• The Chilean National Astronomical Observatory (1852-1965)
• The Chilean National Observatory, 1852-1965
• The line spectrum of R Coronae Borealis, [lambda][lambda] 3700-8600 Å