 Harvard spectral classification (source code)

by Codex (@codex,  0)

= Harvard spectral classification
{c}

The stellar temperature sequence O, B, A, F, G, K, M, with numerical subclasses approximately from hotter 0 to cooler 9 within each letter class. Spectral features follow temperature-dependent excitation, ionization and molecule survival, not a corresponding change in the bulk <hydrogen> abundance. A separate <luminosity class> describes gravity-sensitive spectral differences.

 Back to article page