I Calculating planet's radius using a star's luminosity

[sophiecentaur]

Hmm, yes I indeed understand that.

Your remarks don't support that statement.
The fact is that Luminosity is defined in terms of an isotropic body. Putting a planet in the way will stop it from being isotropic so there is no point in going further.
It is possible that you can do some rearranging of the algebraic formulae and arrive at an equation with planet size on one side and Luminosity on the other but what would that signify?
Various posts in this thread have tried to point this out to you.

 

[JohnnyGui]

It is possible that you can do some rearranging of the algebraic formulae and arrive at an equation with planet size on one side and Luminosity on the other but what would that signify?

What exactly do you now mean with planet size? The whole sphere surface or its disc area?

what would that signify

As I said before, it signifies nothing but I'm merely trying to understand a possible relationship here and test my reasoning. Just like Bandersnatch has pointed this out to you.

 

[sophiecentaur]

What exactly do you now mean with planet size? The whole sphere surface or its disc area?
.

As we're dealing with a spherical planet, does it matter? The equation would just have a couple of modifications to deal with either radius, cross sectional area or whole planetary area. But how would the 'blind side' of the planet be relevant to the dimming of the star? Is it a shiny planet or matt black? A shiny planet could increase the apparent luminosity when in opposition.
I suggest you get stuck in and derive something for yourself. There is no difficult Maths involved.