Calculate Average Temperature of Planet in 0.4 AU Orbit: Albedo 30%

[quasarLie]

Homework Statement

We consider a planet in a circular orbit around a star.
I have to calculate the average temperature knowing that the radius of the orbit is 0.4 AU and that the planet reflects 30% of the incident light

Homework Equations

The Attempt at a Solution

I used this equation
$$F = L/4 \pi D²$$
And
$$F = \sigma T^4$$
So i can have T, but i don't know how to use the albedo
Thanks

 

[gneill]

Did you do a web search on "albedo and planet temperature"?

 

[haruspex]

F=L/4πD²

Please define your variables.

how to use the albedo

What is the contribution of the reflected light to the temperature?
Edit:

consider a planet in a circular orbit around a star... calculate the average temperature

It ought to say a bit more... like, assume the planet rotates on its axis sufficiently fast and has sufficient atmosphere (but no greenhouse gases) that the temperature can be assumed roughly equal over the whole surface. Otherwise the answer can be substantially different.

 

[OmCheeto]

The temperature or output of the star is also missing.

Temperatures of stars in Kelvin:

3000 Proxima Centauri
5800 Sun
9900 Sirius
22000 Bellatrix​

 

[quasarLie]

Please define your variables.

What is the contribution of the reflected light to the temperature?
Edit:

It ought to say a bit more... like, assume the planet rotates on its axis sufficiently fast and has sufficient atmosphere (but no greenhouse gases) that the temperature can be assumed roughly equal over the whole surface. Otherwise the answer can be substantially different.

The planet don't have an atmosphere and it's luminosity is 2/3L (sun). I don't have more information

 

[haruspex]

The planet don't have an atmosphere

if you are told that then you should have included it in the problem statement.
Please try to answer my other two comments.