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## Temperature in Celestia 1.6.1

General discussion about Celestia that doesn't fit into other forums.
Topic author
gironde
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### Temperature in Celestia 1.6.1

Please, would anyone know how is the temperature of planets or other objects calculated in Celestia 1.6.1?

My goal is to frame the calculation of this temperature in LUT5.
In Celestia, the Sun's temperature is provided by the CELX function obj: getinfo (). Temperature.

In Celestia 1.6.1 this value is 5860 K
In Celestia EPV3 (1.7.0 v5229) this value is 5780 K

To determine the surface temperature of a planet, a moon, ... we need a formula that is a function of the temperature of the star, the distance from the body to the star, the albedo,. ..

What is this formula in Celestia?

onetwothree
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BodyTemperature = StarTemperature * ((1.0 - BodyAlbedo) ** 0.25) * sqrt(StarRadius / (2.0 * BodyDistanceFromStar)))

Croc
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Location: Udomlya, Tver region, Russia
BodyTemperature = StarTemperature * ((1.0 - BodyAlbedo) ** 0.25) * sqrt(StarRadius / (2.0 * BodyDistanceFromStar)))

StarTemperature = 5860
BodyAlbedo = 0,37
BodyDistanceFromStar = 149600000

(1.0 - BodyAlbedo) ** 0.25 = 0,890912674
sqrt(StarRadius / (2.0 * BodyDistanceFromStar)) = 0,048230729
BodyTemperature = 251,8004945

onetwothree

onetwothree, please indicate the source of information.
Creator of the GUI "Lua Universal Tools"
25/V/1947 - 30/III/2019

Topic author
gironde
Posts: 383
Joined: 16.12.2016
Age: 66
With us: 2 years 8 months
Location: Montigny-Les-Metz, Grand Est, Lorraine, Moselle, France
The site http://planet-terre.ens-lyon.fr/article/temperature-de-surface.xml
provides this formula for the solar system:
280* [ (1-bodyalbedo) / (BodyDistanceFromStar)^2 ]^0.25
It does not say what 280 represents
for this formula to work outside the solar system, I thought of:
(Tstar/Tsol) * formula

with Croc values, the result for the Earth is 256 K (-17°C), Venus 227K (-46°C), Mercury 404K (131°C)

Thank 'onetwothree', but is this the formula used internally in Celestia 1.6.1

onetwothree
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Croc wrote:onetwothree, please indicate the source of information.

I took it from celestia sources. But you can find it here.

gironde wrote:Thank 'onetwothree', but is this the formula used internally in Celestia 1.6.1
yes, see here.

Croc
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Location: Udomlya, Tver region, Russia
#5by onetwothree
...................
I took it from celestia sources. But you can find it here.

onetwothree, thank
Creator of the GUI "Lua Universal Tools"
25/V/1947 - 30/III/2019

Topic author
gironde
Posts: 383
Joined: 16.12.2016
Age: 66
With us: 2 years 8 months
Location: Montigny-Les-Metz, Grand Est, Lorraine, Moselle, France
And for me too, thank you 'onetwothree'