Definition of "α"

(electrodynamics) The fine structure constant.

1. (in our Universe) a value of approximately 1/137 = 0.0072973525  examples

(classical mechanics) Represents angular acceleration.  examples

(chemistry) Used in chemical nomenclature.  examples

(astronomy) Used to identify some bright star, usually the brightest star, of a constellation, for instance α-Centauri.  examples

(topology) Alexandroff compactification

(astronomy) right ascension  examples