Oh be a find girl. Kiss me right now, smack! Learned in Astronomy 101.
Mnemonics for the
Harvard Spectral Classification Scheme
“The modern stellar spectral classification scheme (also known as the Harvard Spectral Classification Scheme) was created by Annie Jump Cannon through her examination of spectra from 1918 to 1924. ...to reflect the surface temperatures of stars. In order of decreasing temperature, these types were O, B, A, F, G, K. and M. Three additional categories also in the scheme: R, N, and S types, were later realized to represent stars with peculiar heavy-metal abundances… According to astronomical myth, Henry Norris Russell suggested the following mnemonic to assist students in remembering the scheme.” Source
Every Good Boy Does Fine Learned in piano lessons 101
Used by many to remember what the notes in the five main lines of the Treble Clef in Music, representing E, G, B, D, and F from bottom to top.
*F A C E * spaces for the treble clef
BASS CLEF:
God boys do fine always. lines
All cows eat grass. spaces