[headdie]

http://www.bbc.co.uk/news/science-environment-14940885

A planet orbiting two suns - the first confirmed alien world of its kind - has been found by Nasa's Kepler telescope

Ok it's a gas giant so not inhabitable but an interesting find all the same

[Dragon]

Do you realize just how much this increases the amount of stars to take into account when looking for planets?
Until now, double stars were excluded from the search for other planets. This discovery will have enormous influence on the equation used for calculating likelihood of finding extraterrestial life.

[headdie]

Do you realize just how much this increases the amount of stars to take into account when looking for planets?
Until now, double stars were excluded from the search for other planets. This discovery will have enormous influence on the equation used for calculating likelihood of finding extraterrestial life.

I didn't know that, ok so more significant that I thought

[Nuke]

binary systems give me the creeps

Do you realize just how much this increases the amount of stars to take into account when looking for planets?
Until now, double stars were excluded from the search for other planets. This discovery will have enormous influence on the equation used for calculating likelihood of finding extraterrestial life.

i always assumed that such systems were excluded because multiple stars would cause less stable orbits of planets and unstable surface temperatures than your single star systems. you're always gonna have debris left over from star formation, which is likely to coalesce into planets, so i never doubted that binary systems had planets.

[watsisname]

My thought was that you could get planet formation in a binary system, but the planets wouldn't be able to exist in stable orbits for very long if they were too close to the stars, since as you get closer you'd have increasing angular separation between the two most influential masses in the solar system, and they are both moving.

I actually did a test of this a while back using a program called Gravitation 3D.  I've attached the scenario file if anyone else has the program (it's freeware) and wants to look for themselves.  As expected, test particles (originally in circular orbits) too close to the stars either spiral in and collide with them, or get slingshotted right out of the system.  Orbits farther away are stable for longer periods of time, but they still undergo oscillation.  Get far enough away and the orbits are quite stable though, which again you might expect because when you get sufficiently far away the angular separation of the stars goes to zero and you can just consider them as a single stationary object whose mass is the sum of the two.

To my knowledge astronomers have wondered what all of that would mean during the formative phase of the planetary system, since it's the accretion of dust particles that leads to building protoplanets, and if the orbits of those dust particles are oscillating like that then surely the formation process could play out quite differently.  So finding this planet may help shed light on that matter, so that's a great discovery in my opinion.

As far as habitability is concerned, ehhh, I'm not sure.  Clearly you've got variable solar insolation due to the eclipses, unless the stars' orbits are highly inclined relative to the planets, but that would be very unexpected (the orbits should tend to flatten over time, plus it would contradict what you'd expect with the star-formation process).  Anyway, you might get around that problem if one star is larger and more luminous while the other is smaller and fainter, (a reasonable case if you have stars of different masses and therefore size and surface temperature) as then the eclipses won't change the total amount of light being received by the planet nearly as much.  Beyond that, I can't really say.  It's an interesting subject!

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[Kosh]

http://www.bbc.co.uk/news/science-environment-14940885

A planet orbiting two suns - the first confirmed alien world of its kind - has been found by Nasa's Kepler telescope

Ok it's a gas giant so not inhabitable but an interesting find all the same

Ah but gas giants have moons, some like Jupiter have dozens of moons. That being said it is a bit chilly........

[Firstdragon34]

Even though the planet is a gas giant, it would be fun if the moons was populated. It would be a real Pandora, for sure

[deathfun]

Psssh
I saw planets circling double stars in Spore, this is nothing new!

That aside, that's really quite interesting. On the note of habitation, you have to take into account the fact that although it may not be livable for us, doesn't mean it wouldn't be livable for a creature who has evolved to survive in such conditions.

[watsisname]

Quite so, we don't really know much about the extremes to which life can evolve and survive in.  And judging by the existence of "extremophile" organisms found in very hot, cold, acidic, saline, or high pressure environments here on Earth, or even that crazy arsenic-lake stuff found earlier this year, I'd say the odds are pretty good for life being out there on worlds that seem utterly inhospitable to us.

[SpardaSon21]

If we ever find a desert planet orbiting a binary, I want it named Tatooine.

[Astronomiya]

The planet is not habitable.  The stars are dim enough that the surface temperature is something in the vicinity of -70 C at best (or that may have been 70 K; don't remember, but anyway, ****ing cold).  If it had a Europa like moon, that might have life on it, though I consider the possibility of life on Europa to be remote.

A number to keep in mind is that for a sufficiently low-mass planet (really, anything Jupiter class and below will do), the required separation ratio between the binary's separation and planet's orbital radius/semimajor axis is about 3:1.  The stars in the system are a .7 and .2 solar mass pair with an orbital period of about 41 days, while the planet is at something like 200 days, so its orbit is very stable. 

[Firstdragon34]

It be even more awesome if the desert planet is like Arakis or Dune, the spice must flow! 

[deathfun]

The planet is not habitable.

By Human standards

[Nuke]

If we ever find a desert planet orbiting a binary, I want it named Tatooine.

unless it had sandworms

It be even more awesome if the desert planet is like Arakis or Dune, the spice must flow! 

meh, beat me too it.

[JCDNWarrior]

If we ever find a desert planet orbiting a binary, I want it named Tatooine.

unless it had sandworms

Sandworms on this planet, mindworms on the other (Alpha Centauri), galaxy of worms

[Black Wolf]

As I understand it, the problem with binary systems isn't that there're no stable orbits, it's that there're no stable orbits which keep a planet in the Goldilocks zone. So while life is possible, that makes it much harder.

[Firstdragon34]

Unless there is some kind of quantum gravity influence on the planet!   

[Nuke]

As I understand it, the problem with binary systems isn't that there're no stable orbits, it's that there're no stable orbits which keep a planet in the Goldilocks zone. So while life is possible, that makes it much harder.

thats about it. but you must also consider that with a binary system the goldilocks zone itself tends to fluctuate, moving inward in areas where one star eclipses the other and further out where both stars are visible, making the zone slightly eliptical and rotating in sync to the lesser stars orbit around the other. figuring out how much the zone varies requires math that i dont feel like doing. but the instability of the zone compounded with the instability of the orbits makes the likelyhood of the system supporting life much less, if not impossible.

[watsisname]

Not necessarily.  You might be able to have life on tidally-heated moons orbiting gas giants or whatnot, but without real-world data to back this up as of yet, that's still an open question.

And Nuke, you have it pretty much right about how the eclipses will affect the habitable zone.  This will act to make the habitable zone fluctuate for any planets that share the same orbital plane as the stars.  Judging from how we expect solar systems to form and evolve, that should be true for most cases -- the planets should generally orbit in about the same plane as the stars' orbital/rotational planes.  However, the severity of this effect also depends on the ratio of the diameters and luminosities (which depends on the mass and age), and orbital separation of the stars in question.  If one star is sufficiently larger than the other then eclipses won't have as much of an impact on the amount of light received by an orbiting planet.  And if the stars are separated by a great distance, then you can have separate, stable habitable zones around one or both of those stars.

I did manage to find a fairly decent article on this subject, might be a good read for ya.