Extreme Planetary Features vs realism

[BlackChakram]

The setup of the moons would mostly affect the tides. Instead of a nice pattern of tides twice a day, you'd get a much more irregular and complex pattern of tides spaced oddly and of different sizes. Maybe you'd see some increased tectonics as well, but not likely to be much.

With the two suns, you wouldn't see much effect from the farther one. It may increase the average temperature of your planet by 5-15 C, but that's about it. If it's far enough away to mostly be just a bright star, then nearly all its heating and lighting effects will be too small to notice.

That's all that should be affected. Magnetism, north pole, seasons, and weather should all be pretty much unaffected.

[Naima]

how would rotate the suns around each other and how the moons? I can use any tool to calculate those?

[BlackChakram]

If you wanted to get some exact numbers, you'd probably need to use some software like Sandbox Universe. But essentially, here's a rough idea:



The star on the left would be your main one. The band around it represents the area where planets can orbit. Your planet with its two moons would be in this area. You na use any remotely realistic numbers here for orbit distance and moon distance. Your dimmer, other star is the one far on the right. Numbers on this scale are about as precise as you can get. You can make up anything you want as long as its within these ranges.

[Azélor]

If you wanted to get some exact numbers, you'd probably need to use some software like Sandbox Universe. But essentially, here's a rough idea:



The star on the left would be your main one. The band around it represents the area where planets can orbit. Your planet with its two moons would be in this area. You na use any remotely realistic numbers here for orbit distance and moon distance. Your dimmer, other star is the one far on the right. Numbers on this scale are about as precise as you can get. You can make up anything you want as long as its within these ranges.

i tried the software but he has a serious problem with binary systems. You need to folow the tutorials to get it to work and still. My planet was at a good 50 AU from the center and was still unstable.

I calculated the brightness of a star at around 75 AU. A big white dwarf... Nearly 3 time brighter than Venus and 600 time fainter than the full moon. By comparison, Sirius A, the brightest extra solar star as seen from Earth is about 50-60 times dimer than our old star. i used this formula to calculate the brightness : Inverse-square law - Wikipedia, the free encyclopedia
I suppose this formula can also be used to determine the energy dissipation ? the impact on temperature)

infos from that topic: http://www.cartographersguild.com/co...rophysics.html

[BlackChakram]

Alright. I've whipped up some equations with some sample math. It was easier to do this as a word document. Post questions if you have 'em!

[Azélor]

so if the brightness of a star is around -16 in scale of magnitude, it's more than 100 times dimer than the Sun ?

the apparent magnitude is -6 from the planet. I got that number using the inverse square law. I tried you formula and I got the same numbers .

so if I understand correctly, the second star increases the temperature by 10.38. That is a huge impact considering the star is at 216 AU. The difference between a temperate world and a tropical one.
In my case I get 9.37 degrees. I was going to wonder If something was wrong with the formula, but no. I tried with Neptune and got similar numbers to the wiki.

0.008 times is the brightness of the star compared to the Sun and it is located at 75 AU.

[BlackChakram]

all sounds about right to me!

And yeah. 10 k does make a difference. But that can easily be undone by reflective cloud cover, planetary tectonic activity, or any other number of factors.

[Azélor]

I have some questions about astrophysics. They are mainly related to the CWBP2.

One of our planet is tide locked to the star. The star is a G star just like the Sun. I was wondering how close the planet need to be in order to become tide locked. It's about the size of Mercury.

I would also greatly appreciate if you could give me your opinion on this topic : http://www.cartographersguild.com/co...tml#post252715

[BlackChakram]

Hm... the equation for tidal locking is really complicated. But even Mercury isn't tidally locked, so you'd have to do one of two things: 1) Wait longer, as all things tidal lock with time, or 2) get closer.

I'd go with option 2 and do something like 0.2 AU. But this is just a rough estimate. Like I said, the equation is complicated.

[xpian]

@BlackChakram - For tidal locking, you could also use some special circumstances, could you not? I mean, sure, it would take billions of years for a planet like Earth to tidally lock to a star like the sun, but what if that mars-sized object that struck the Earth long, long ago--the one that caused the formation of the moon--had hit us at *just the right angle*? What if it had hit Earth in such a way that it slowed the planet's rotation dramatically, allowing it to settle into a tidally-locked situation.

These things happen. Just look at Uranus: the planet orbits ON ITS SIDE. That's one huge-ass planet, and it didn't start off pointing its pole down near the ecliptic. No, something extremely violent happened to Uranus in the very distant past, and it completely and permanently put the planet in a goofy orientation.

Even if you're not going to invoke gods or aliens as the reason why your planet is tidally locked, you could invoke bizarre circumstance.