# Temperature of a planet a distance from sun!

#### tetris11

1. Homework Statement
Hi,
A spinning shiny red-appearing planet at 130 billion km from the sun, has a diameter of 1700km.
Estimate temperature of planet using simple heat balance equation.
Estimate also the temperature obtained by Wien displacement law.

2. Homework Equations
I've been given no equations, but I know that shiny planets have an Albedo =1, and the wavelength or red = 650nm, which is useful for the Wien law $$\lambda$$=b/T, where T is kelvin and b = 2.9x10^-3

Temp of sun = 5800k

3. The Attempt at a Solution
I don't know what equation there is to use! I've looked on the internet and gotten this eq.

Tp = Ts((Rs/D^2)^(0.5))

where Tp is temperature of planet, Ts of sun, Rs radius of sun, D distance to planet.
help!

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#### MathematicalPhysicist

Gold Member
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