
[BASIC OPTIONS AND TERMINOLOGY]

       In Nightfall, the <Primary> is the star passing in 
       front of the other one first, and the <Secondary> 
       thus is the star first eclipsed.

       The <mass ratio> is mass(Secondary)/mass(Primary), 
       thus it is higher than one if the Secondary is 
       more massive.

       The <inclination> is the angle, under which the 
       plane, in which the two stars orbit each other, is 
       seen from earth. Only for inclinations near 90 deg 
       (near edge-on view) an eclipse is possible.

       To define the sizes of the two stars, you have to
       specify their <radii>, which are
       defined in units of solar radii (i.e.
       the radius of the Sun).

       The <temperature> is the surface temperature of the 
       star. The luminosity of a star depends on its 
       surface area (i.e. size) and the temperature.

[Limiting values]

	  To avoid numerical problems, parameters are limited 
	  to reasonable values. These are:
{
          mass ratio:              0.0001 - 10000
          inclination:             0     - 90
          temperature:             350   - 350000 
}
	  If a value is out of range, it will be reset to the 
	  lowest/highest allowed value.


