THE MACHO PROJECT LMC VARIABLE-STAR INVENTORY .5. CLASSIFICATION AND ORBITS OF 611 ECLIPSING BINARY STARS

We report the characteristics of 611 eclipsing binary stars in the Lar ge Megallanic Cloud found by using the MACHO Project photometry databa se. The sample is magnitude limited, and extends down the main sequenc e to about spectral type A0. Many evolved binaries are also included. Each eclipsing binary is classified according to the traditional schem e of the General Catalogue of Variable Stars (EA and EB), and also acc ording to a new decimal classification scheme defined in this paper. T he new scheme is sensitive to the two major sources of variance in ecl ipsing binary star light curves-the sum of radii, and the surface-brig htness ratio, and allow greater precision in characterizing the light curves. Examples of each type of light curve and their variations are given. Sixty-four of the eclipsing binaries have eccentric, rather tha n circular, orbits. The ephemeris and principal photometric characteri stics of each eclipsing binary are listed in a table. Photometric orbi ts based on the Nelson-Davis-Etzel model have been fitted to all light curves. These data will be useful for planning future observations of these binaries. Plots of till data and fitted orbits and a table of t he fitted orbital parameters are available on the AAS CD-ROM series, V ol. 9, 1997. These data are also available at the MACHO home page (htt p://wwwmacho.mcmaster.ca/). (C) 1997 American Astronomical Society.