Eclipsing Binary Stars

by John Talbot
Three dimensional Java simulation of stars that move about each other in elliptical orbits whose orientation with respect to the observer is such that an eclipse will occur when one passes in front of the other.

Your browser doesn't support Java, the above image is what you would see.

Bug : move mouse off panel after changing sliders.
Panel Description
Light Curve Plots the light intensity variations during one orbit. The orbital phase can be set by clicking in this window (this will stop the animation if one is runnning). You can also click and while holding down the mouse button drag the mouse horizontally for more precise control over the animation speed and direction (bug: currently disabled).
Earth Perspective Three dimensional animation of the binary star system. By clicking in this window you can stop and restart the animation.
Blue Star Controls the luminosity, radius and mass of the blue star member of the system.
Red Star Controls the luminosity, radius (in units of orbital seperation) and mass of the red star member of the system.
Orbital Parameters Controls the orbit inclination, eccentricity (disabled) and the number of light samples (disabled) during one orbit.
Note: All these parameters can also be set by applet PARAM tags (see the details at the end ot this page)

For a detailed description of eclipsing binary star visit Dan Bruton's excellent page, consult Goldstein (1981) for the equations.


If the laser star theory is correct, quasars are stars in our galaxy. We expect that some of them would be binary systems. Furthermore, we could predict with certainty that a small percentage of those binary systems will produce eclipsing binary light curves.

Although the light curves of most quasars has not been followed with enough time resolution to detect eclipses, there have been reports that some quasars have a regular periodic change in their luminosity. This fact is almost impossible to explain within the standard cosmological quasar theory, they think it might be a planet in a tight orbit around a central black hole.

The laser star theory offers a much simpler interpretation:

The periodicity in the quasar luminosity is caused by an eclipsing binary laser star !

These light curve observations confirm one of the predictions of the laser star theory. Another prediction was that quasars should have significant proper motion, just like other star in our galaxy. This has also been confirmed and both these facts are very strong evidence in favor of the laser star theory.

Amateur astronomers with CCD cameras have the ability to perform the neccessary observations to determine if a quasar is an eclipsing binary star system and also to track the proper motion of quasars across the sky.

Applet Details

The Java source code is available :

The subroutine in this applet assumes spherical stars and circular orbits. It doesn't include effects such as

  1. Elliptical orbits (eccentricity controls have no effect)
  2. Limb darkening
  3. Gravitational and centripedal distortion of the stars
  4. Radiation reflection (one star bouncing light off the other)
Although all the parameters can be controlled from within the applet's user interface, most of them can also be preset with the PARAM applet tag within the HTML web page :

    <APPLET CODE="Binary" HEIGHT=400 WIDTH=600>
    <PARAM NAME="blueMass" VALUE="50">
    <PARAM NAME="redMass" VALUE="50">
    <PARAM NAME="blueRadius" VALUE="0.25">
    <PARAM NAME="redRadius" VALUE="0.25">
    <PARAM NAME="blueLuminosity" VALUE="0.5">
    <PARAM NAME="redLuminosity" VALUE="0.25">
    <PARAM NAME="inclination" VALUE="85">
    <PARAM NAME="eccentricity" VALUE="0">
These options could also be used on separate HTML web pages to create a library of light curves from various binary star systems. A comparison could then be made between observational data and their synthetic approximations by adding to each page a published light curve from the litterature or the AAVSO.

Applet created by John Talbot, July 1997; the astrophysical part of the program was translated to Java from a BASIC subroutine. originally by Dan Bruton, October 1995. The layout and general functionning of this applet is based on his Windows 95 program Ebstar v1.0a2 (Midnight Kite Software).


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