Le 16-01-25 05:22, Sven Littkowski a écrit :
> I found this table on the big, wide Internet, but I still need some
> idea, how to express each star type's luminosity in POV-Ray. Ideas and
> suggestions welcome.
>

The full list is : OBAFGKMN
There is a whimsical mnemonic phrase used to remember them:
O Be A Fine Girl, Kiss Me Now.

O0 been blue tending on violet, and N9 been deep red, usualy belonging 
to red dwarf stars.
This classification deal only with the spectral type.

The numerical values following goes from 0 to 9

Basicaly, each code equate to a black body temperature.
You can find those temperatures online.
Finaly, you can use CIElight.inc to get the appropriate RGB values.

Next, for the luminausity, you need to use the Magnitude of the star.
There is the apparent and absolute magnitude.
Apparent is how bright the star appear from the Earth, while the 
absolute magnitude use a normalised distance.

As for the actual size of the star, there is no absolute way to get it.
There are 3 main size families: Main sequence, dwarf and giant. There is 
also the super giant class that is actualy an extention of the giant class.

On the main sequence, the star size can range from 0.1 Sun radius (type 
N), to near 1000 Sun radius (type O0)
The O type stars from the main sequence are also part of the giant 
class, while the N type are also part of the dwarf class.

For the dwarf stars, the radius stay around Earth radius to 0.15 Sun 
radius regardless of the spectral type.

All giant class stars are at least 500 times the Sun's radius, and super 
giants are at least 10000 Sun radius, some been large enough to contain 
Neptune's orbit.


I don't remember how many astronomy books I read in my life... But, it's 
a LOT!

Alain

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