WD2007Department of Astronomy
Prof. Dr. Kallrath

The Eclipsing Binary Program WD2006

The Eclipsing Binary Program WD2006 has been developed by Josef Kallrath, and, in those parts related to the stellar atmospheres, by Eugene F. Milone; WD2007 is currently under development.

The program runs under the operating system LINUX as well as in a DOS Window/DOS box under Win95, Win98, WinNT, Win2000 and WinXP. It should also run under other UNIX operating systems and CygWin; however, this has not been thoroughly tested.

WD2006 is a Fortran-based wrapper around the Wilson-Devinney program WD (=LC+DC) developed and distributed by Robert E. Wilson (University of Florida) to compute eclipsing binary light curves. The term light curves is here used in the general sense of eclipsing binary observables; see, Kallrath & Milone (1999) among other observables, and to analyze data, i.e., to fit light curves or merely to compute a synthetic light curve. WD2006 has tight link with the original WD code, and it calls the WD subroutine DC and other subroutines called subsequently. Therefore, it is compatible regarding the astrophysics. The package itself is still maintained and further developed solely by Josef Kallrath. The documentation has been improved significantly and, from 2005 on, is maintained by J. Kallrath and E. F. Milone.

It should be understood that modeling eclipsing binaries and solving inverse problems in such a context is a major research effort and requires some expertise to use the software effectively. Wherever possible, great effort has been invested to make the software as stable as possible.

WD2006 has been developed within the framework of a several preceding software packages named LCCTRL, WD93, WD95, WD98, and WD2002. WD2002 was the first release that combined all previous developments and included all stellar atmospheres improvements added by E. F. Milone and C. R. Stagg, and was also the first release which ran under LINUX and other UNIX operation systems.

WD2006 adds simulated annealing as a minimization algorithm, and produces tables of absolute dimensions, and, in particular, LaTeX output tables. It also supports and embeds a Fortran subroutine for the computation of limb-darkening coefficients as provided by Walter Van Hamme.

The procedure for creating the flux files is described in the appendix along with changes to the atmospheres option in WD programs. The use of the flux ratio files that make use of Kurucz atmospheres models are coded in Subroutine ATM2000 (which replaces subroutine ATM) by C. R. Stagg.

We provide the LaTeX source file, docu.tex, in the WD2006/DOCUMENT directory to encourage the new user to add appropriate comments, corrections or extension directly into this file. That way, we can eliminate problems in a short time. We also appreciate feedback in case you experienced difficulties.

A final remark: Currently, there are at least three programs available based on the Wilson-Devinney approach and program. At first, and always the most up-to-date in terms of the astrophysics, is the original WD program with a lot of functionality added over the years; Bob Wilson is actively developing and maintaining this program. Most analyses of eclipsing binary stars are performed with this program. Second, the WDxxxx program described on this web page. This program runs fully under both Linux and Microsoft Windows operating systems, and there is a about a dozen of papers in which this program has been used for eclipsing binary analyses. Third, the GUI wrapper PHOEBE developed by Andrej Prsa. This program is handy and nice to use and has an active user group (it is not clear whether the GUI works with Microsoft operating systems). The final conclusion is: it depends on one's needs and working style preferences which program to chose.

WD2006 can be downloaded as the password-proteced file wd2006.zip [left mouse click]. The zip file contains the executable for Microsoft Windows, documentation, test examples, but not the source code.

Please contact the author and ask for the password to unzip the zip-file.

Copyright © 2007, Josef Kallrath, 30th Dec 2007