Bayer designation
Bayer assigned a lowercase Greek letter (alpha (α), beta (β), gamma (γ), etc.)[3] Bayer did not label "permanent" stars with uppercase letters (except for A, which he used instead of a to avoid confusion with α).However, a number of stars in southern constellations have uppercase letter designations, like B Centauri and G Scorpii.These letters were assigned by later astronomers, notably Lacaille in his Coelum Australe Stelliferum and Gould in his Uranometria Argentina.In addition, Bayer did not always follow the magnitude class rule; he sometimes assigned letters to stars according to their location within a constellation, or the order of their rising, or to historical or mythological details.)[6] Bayer then repeated the procedure for the stars of the 2nd magnitude, labeling them from gamma through zeta in "top-down" (north-to-south) order.23 Bayer assigned the first three of these stars a Greek letter from both constellations: Alpha Andromedae = Delta Pegasi, Beta Tauri = Gamma Aurigae, and Nu Boötis = Psi Herculis.[9][10] A further complication is the use of numeric superscripts to distinguish neighboring stars that Bayer (or a later astronomer) labeled with a common letter.