[Space] Making a solar system with 3 (semi-) habitable planets?

[Fred Brackin]

Originally Posted by johndallman

Does the goldilocks zone get wider if your star is really large and luminous? Obviously you'll have very long years, but that's bearable.

You will rapidly run into stars being too short-lived for planets to cool and evolve life,

From one table I looked at you _might_ be able to go from Sol's G2 to an F8. There's a distinctly non-linear relationship between mass and lifespan on the Main Sequence table. You can't really use stars that are much larger than Sol.

[Anthony]

Originally Posted by johndallman

Does the goldilocks zone get wider if your star is really large and luminous?

Yeah, but anything above around 2x solar luminosity doesn't live long enough.

[vicky_molokh]

Originally Posted by Anthony

Yeah, but anything above around 2x solar luminosity doesn't live long enough.

I might be mistaken, but all checks so far prove that luminosity doesn't help. The orbits get bigger, but the ratios stay the same.

Oh, and I just noticed that reducing the hydrographic coverage of the distant world below the normal minimum of 50, down to 10-20, allows one to increase distance a little bit more.

[Anthony]

Originally Posted by vicky_molokh

I might be mistaken, but all checks so far prove that luminosity doesn't help. The orbits get bigger, but the ratios stay the same.

The exclusion zone for a planet most likely does not increase as fast as the orbital radius, though Space doesn't follow that assumption.

[vicky_molokh]

Originally Posted by Anthony

The exclusion zone for a planet most likely does not increase as fast as the orbital radius, though Space doesn't follow that assumption.

Why would it? The distance the planet has to be from the sun depends on how much of the given energy it retains (depends on the properties of the planet) and how much energy is given. Energy given depends on luminosity and distance. If we adjust the star to double the energy for one planet, it will double for all other planets.

[Pragmatic]

How about doing two suns in close orbit? Their masses combine, and their luminosity, which changes the results of the formulas.

I found that the best I could do, when playing with the numbers, is getting a warm/chilly or tropical/cool pairs... (You have to tweak, like changing the density or atmospheric mass, or having extreme high/low levels of water to change the albedo.)

[vicky_molokh]

Originally Posted by Pragmatic

How about doing two suns in close orbit? Their masses combine, and their luminosity, which changes the results of the formulas.

End result is that the luminosity sum is the same for both planets, unless the stars are far apart.

Originally Posted by Pragmatic

I found that the best I could do, when playing with the numbers, is getting a warm/chilly or tropical/cool pairs... (You have to tweak, like changing the density or atmospheric mass, or having extreme high/low levels of water to change the albedo.)

By making the further planet only have 20ish hydrographics, I think I can make the earthlike planet totally Earthlike in climate, if I want to. Though at this point, I'm getting worried about deriving regional climates from the planetary data. Currently looking into one of the older threads on the topic.

[Anthony]

Originally Posted by vicky_molokh

Why would it?

Because the exclusion zone (not the life zone) is the zone where the planet's gravity is sufficient to eject all other objects from its orbit.

[vicky_molokh]

Originally Posted by Anthony

Because the exclusion zone (not the life zone) is the zone where the planet's gravity is sufficient to eject all other objects from its orbit.

Aren't exclusion zones roughly comparable to to Orbit×1.4 and Orbit/1.4? (I.e. vaguely less, such that at a ratio of 1.4 is more-or-less safe from the other orbital body's gravity.) I thought those numbers come from laws of astrophysics, not made up in G:Space. Are they real-life or not?

[Flyndaran]

I thought the exclusion zone would be about the no closer than .14 A.U. no matter the ratios.