Fourier Analysis of the Light Curves of Eclipsing Variables, XVIII
Abstract
The aim of the present paper has been to establish explicit expressions for the ‘photometric perturbations’mathfrak{P}_{2m} in the light changes of close eclipsing systems, arising from the mutual distortion of the components, for any type of eclipses — be these occultations or transits; partial, total, or annular — and exhibiting arbitrary distribution of brightness (limb or gravitydarkening) over the apparent disc of the eclipsed star. These perturbations have been expressed in terms of certain general types of series that can be easily programmed for automatic computation. They represent a generalization of results previously obtained by Kopal (1975) or Livaniou (1977, 1978) in so far as the expansions derived in this paper hold good for any real (not necessarily integral) value ofm>0. As such, they can be used to free from the photometric proximity effects within eclipses the empirical momentsA _{ 2m } of the light curves of nonintegral orders, and the task performed within seconds of real time on highspeed automatic computers now available. Closedform expressions for such perturbations, obtaining in the case of total eclipses, are given correctly to terms of first order in quantities which represent the distortion of each component.
 Publication:

Astrophysics and Space Science
 Pub Date:
 August 1978
 DOI:
 10.1007/BF00639336
 Bibcode:
 1978Ap&SS..57..439K
 Keywords:

 Eclipsing Binary Stars;
 Fourier Analysis;
 Light Curve;
 Stellar Spectrophotometry;
 Variable Stars;
 Computer Programs;
 Perturbation Theory;
 Recursive Functions;
 Astrophysics