Absorption Lines and Curve of Growth

• observed absorption line spectra
  • the Sun
  • mystery star (spoiler)
  • interstellar medium lines of potassium and lithium towards zeta Ophiuchi, and in the SMC
• contributions to linewidths
• profile functions
• line depth and curve of growth: wavelength space, velocity space
• online catalogs of line wavelengths and oscillator strengths here
• hydrogen lines and the Lyman limit

Awesome Example: Stellar Classification

• dwarf spectral sequence here and here
• O star, DA white dwarf
• interpretation--ionization diversity and the dominance of hydrogren: Cecilia Payne-Gaposhkin PhD Thesis 1925