Observatory, Nantucket, Massachusetts
determination of the period of a short-period variable star is, mathematically,
a simple procedure. In practice, however, the analysis of one star may require
weeks or even months of effort. The main difficulties arise from a lack of data
and from a periodicity which is often inherent in the observations themselves.
This paper outlines the method used at the Maria Mitchell Observatory for
determining periods from photographic observations. To give the reader an
understanding of the practical problems encountered, each step is illustrated
with data on Variable 13,* an RR Lyrae star in Coma Berenices discovered by Dr.
Dorrit Hoffleit in 1969.