Calculation of the habitable Zone around a star

[Thot]

Hi,

Im about to make a solar system wich should have a habitable planet, but i dont know where to put this planet since the star isnt as big as our sun. So my suggestion is: A function that lets you display a 3 dimensional habital area (sphere shape) around your stars.

To the mathematical part:
 I found a great article on wikipedia to this subject:

http://en.wikipedia.org/wiki/Habitable_zone

So far i think it would be easy to manage that, because its a really simple formula for getting the spheres diameter. But theres one problem wich maybe needs a change in the creating options of stars: In this formula is a term wich needs the bolometric luminosity of the star. (L_star)


I hope this problem can be solved, maybe with a option wich lets you control the brightness of the star according to our sun. for example: 0.8 L_sun

I hope you got my point. It would be really great not at least because the existence of life in other starsystems is one of the most interesting terms in modern science.

Theres also another term I thought about: As most of you surely know, there can also be habitable planets in binary or more-star systems. Now I think in thos systems its more complicated but not impossible to display the "habitable sphere". I think on just have to consider, that the rayintensity in the overlapping areas of the two star enviroments behave different, because theres the radiation of two stars.

So, would that be possible to manage? Would be sooooo great!

greetz
 Thot

[FGFG]

I think that your idea is cool and not so difficult 

The equation is based just on the luminosity of the star(s) so it wouldn't be so hard to use in systems with more than one star (simply the shape wouldn't be a sphere); however i'm not a programmer.

I think that you couldn't change the luminosity of a star, but just its dimension (if you want a real star). You couldn't put a very high luminosity on a white dwarf or a black hole   

FGFG

as usual sry for my bad English

[Thot]

Well, my english is not much better ^^

You are right.  I also think that the luminosity depends on the diameter and maybe some other attrbiutes of the star, wich are maybe already given in US. I really hope that this can made possible and will be set on the to do list.

[Thot]

Ive got an idea

If you are calculating the luminosty of the star, you also could show its emitted light graphically. Based on this US could show wich regions of the planets are lit and wich are dark (Day/Night effect).
Even in a binary starsystem you could see how much the other star does effect the brightness of day or the darkness of night on a specific planet.

Am I right with this guess? or is this more complicated than i think?

[FGFG]

i don't know how complicate it is, but i know that Dan is working to make planets surfaces illuminated by the stars (now the planets and even stars are illuminated from just a costant direction) if it adds the quantity of light that hitts the planet there wouldn't be problems. Just some equations to apply 

[Thot]

Great!
Oh I simply love this! I am constructing a solar system for the novel I am writing. Its simply great to work with this program. If it could even simulate this nightdaything it would be simply wonderful because I am about to construct an own calendar for one of this planets.

[FGFG]

i think that you have read Nightfall by Azimov then.... A bit strange system....

[Thot]

No never heard about this novel. What I am doing is writing a novel, and for this novel I am now constructing a working solar system
Without US I never could do that so fast and so precisious.

[FGFG]

Nightfall is one of the best sci-fi small stories of all the times. I really suggest you it. 

However the described system have 6 suns: 1 central, whith another orbiting it and other 2 binary systems orbiting the first. Into this caos there are 2 stabile planets (!); one of them habitable. You can realize that night isn't so frequent... 

[Thot]

Wow^^ and i thougt my system is quite strange.
You say only 2 stable planets? I can imagine that because nearly every object in this chaos should be thrown out by one the stars, sooner or later

Wonderful what fantasy can do

[FGFG]

well they aren't so stable, but they remain in the system because.... ehm...... read the novel 

[Thot]

Oh I could imagine the answer^^ In my novel there is even a planet wich could never be that stable without a little bit of technical help 

[FGFG]

Thinking about it....  Luminosity is one of the things that are needed in U.S. It could determinate the superficial temperature of a planet (without atmosphere)  like Mercury

Also the lenght of day and night is needed... the face of Mercury turned towards the sun is 450 Celsius if i remember well, and the face turned towards the outside of the system is -150 Celsius because of his very long day (2 of its years). It's the same thing that happened to our moon ==> It shows us its heavier face   Even Earth is slowing down! 

[Thot]

to mercury: what mercury does is synchronous rotation. i think nearly everybody should know this and I know that this is possible in U.S. without bigger problems,
but can you also change the tilt of the axe? this would also be important for the temperature in different regions of the planet.
for example earth has a tilt of 23.4°.

[FGFG]

You're right  I forgot the axis. It's even more important for Uranus . However in universe sandbox you can't change the axis of a planet with this relese. I don't know if it is on the "to do" list

[BlackBolt]

A small star can be brighter than a bigger one... A blue dwarf is definitely brighter than a brown dwarf though 

[Thot]

You are right. But you can calculate the luminosity of a star. For mainsequence stars there is a direct relation between their mass and their luminosity:



For stars of other types i think there are similar relations

[Dan Dixon]

Great suggestion and thanks for the wiki link. I really like this idea, but again, no promises on when it will be added (so much to do, so little time).

And it's true that this shouldn't be too difficult to add. The hardest part about this (aside from figuring out how to integrate this with the already semi-jumbled interface is calculating the luminosity of all possible stars (and not just those on the main sequence, as that's straightforward).

Other things that effect habitability that won't be considered in the 1st pass of this feature: tilt, rotation speed, or atmosphere of a planet.

i know that Dan is working to make planets surfaces illuminated by the stars (now the planets and even stars are illuminated from just a costant direction)

While it seems that it would be related, calculating luminosity is a completely unrelated feature from getting stars to illuminate light. Getting the light working well will require some custom DirectX shader work. Calculating the luminosity won't have anything to do with the graphics system.

you can't change the axis of a planet with this relese. I don't know if it is on the "to do" list

Yes. Changing a planet's axis is on the definitive list of future features.