An Etymological Dictionary of Astronomy and Astrophysics

A classification of stellar spectra published in the Henry Draper catalogue, which was prepared in the early twentieth century by E. C. Pickering and Miss Annie Canon. It is based on the characteristic lines and bands of the chemical elements.
The most important classes in order of decreasing temperatures are as follows: O, B, A, F, G, K, M.

See also: Harvard, named for John Harvard (1607-1638), the English colonist, principal benefactor of Harvard College, now Harvard University. → classification