Abstract
A mathematical method for identifying the correct period of a variable star from a small number of unequally spaced observations is presented. Previous methods using Fourier-transform and least-squares techniques are reviewed. The true-string-length approach of Burke et al. (1970) is refined by scaling the observations to place equal emphasis on the observational and periodic members of the equation. It is shown that the minimum string length corresponding to a correct variable-star period will lie between 1.4 and 1.8. The effect of random error is considered, and criteria for predicting the number of false periods that will be generated by the method are presented. The computational routine is described. The method is demonstrated on several stars, and a new orbit is characterized for 17 Lyr, a spectroscopic binary observed by Abt and Levy (1976). An advantage of the method is seen in the fact that it can estimate the period of a variable after as few as 20 observations, allowing the timing of further observations to be planned efficiently.
Author
Dworetsky, M. M.
Journal
Monthly Notices of the Royal Astronomical Society
Paper Publication Date
June 1983
Paper Type
Astrostatistics