How do I calculate the amount of sunlight a planet gets?
I'm working on a planet and I want to know what is the maximum amount of sunlight my planet gets in lux (for Earth It's 120000 lux).
My planet orbits an M4V class red dwarf that has a mass of 0.22 M☉, radius of 0.16 R☉ and a temperature of 3000 K. The planet's semi-major axis is 2.3 AU.
Please also include the formula or program you used to calculate the answer. If you need any additional info I'll add it.
This post was sourced from https://worldbuilding.stackexchange.com/q/122190. It is licensed under CC BY-SA 4.0.
1 answer
Calculating flux
I think a slightly more helpful quantity to calculate is the flux received by the planet - the power per unit area from the star. The mean flux on Earth is the solar constant,
Why should we use flux instead of lux?
- It's easier to calculate. And when I say easier, I mean much easier. Lux is a lot more complicated.
- It's great for calculating things like the effective temperature of a planet.
- It's much more commonly used in this sort of scenario.
I used stellar models by Eric Mamajek to find the star's luminosity - he gives a
I've written a Python program to calculate the flux received on a planet based on a given spectral type, using those models. It should be a quick shortcut for you in the future.
Astronomical lux
It's claimed that you can convert between a star's apparent magnitude in the V-band (
0 comment threads