[vsnet-chat 99] Re: Times of minima

[Taichi Kato <tkato>]

Jim Caffey wrote:

> We use the midpoint of the primary eclipse as phase 0.00, and exactly 1/2 
> the period later as phase 0.50.   Therefore, one eclise, the primary is 
> ALWAYS defined as the phase 0.00, then the secondary eclipse would be 
> away from phase 0.50 for eliptical orbits.,.. for circular, they are at 
> phase 0.50.
> 
> The midpoint is also deinded as the most loss of light.

    In non-symmetric eclipse light curves (which mean non-uniform or
non-symmetric distribution of surface brightness on eclipsed bodies),
I believe this definition may not work well, unless some kinematic definition
(e.g. the conjunction time of the centers of gravity of two stars) is
tightly bound.

    The "most loss of light" definition is also problematic in practice
when applying to total eclipses.

Regards,
Taichi Kato

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