Solon Bailey was an American astronomer who joined the Harvard College Observatory staff in 1879 and was for many years in charge of the Harvard southern station at Arequipa, Peru. His studies of globular clusters led to the discovery of "cluster variables," now known as RR Lyrae stars.

 

Bailey types

Bailey types are a classification of RR Lyrae stars according to the shape and amplitude of their light curves, devised by Solon Bailey in 1899. Types a, b, and c were defined originally, but types a and b are usually combined today. RRa stars show a sharp rise to maximum followed by a slow fall to minimum; RRc stars have a smaller amplitude and a rise and fall of equal length.