Tatooine-like Planet Discovered

ATP writes "CNN is reporting that a planet has been discovered in a solar system with 3 suns. The observation brings into doubt the theory stating that planets form from the dust orbiting around a single sun. The discovery also resulted in a new method of searching for extrasolar planets-- until now most searching focused only on single-sun systems."

Tatooine has 2 suns...

[isd_glory]

Come on... even google knows how many suns there are.
http://www.google.com/search?q=tatooine+suns [google.com]

Not really Tatooine-like...

[Owndapan]

As noted by The Register [theregister.co.uk], the planet is not in a galaxy far, far away, but a mere 149 light-year jaunt through our own Milky Way.

Re:Tatooine has 2 suns...

[Anonymous Coward]

The 'water planet' named 'Trisol' on Futurama has three suns.

Episode: 1ACV07 - My Three Suns [gotfuturama.com]

not like Tatooine...

[Honor]

From the article:

The planet, a gas giant slightly larger than Jupiter, orbits the main star of a triple-star system known as HD 188753 in the constellation Cygnus.

Unless I missed something major when watching the movies, Tatooine isn't a gas giant...

Re:More changes for next release of star wars...

[attemptedgoalie]

As depressing as it is, I remember reading the Empire Strikes Back Trivia Guide, and the suns were Tatoo I and Tatoo II.

No 3rd sun in that system, according to that source.

Re:Like Tatooine?

[Short Circuit]

Be careful about that second link. Every time I open the page, Norton Personal Firewall catches an intrusion attempt:

A computer with the IP address 0.0.0.0 sent information that is characteristic of the HTTP_ActivePerl_Overflow attack.

Uh, no.

[jd]

Most extrasolar planets have been discovered by the wobble of the sun, due to the planet's gravity. Most of the rest have been observed due to abnormal infrared images (gaps or unexpected reflections). Some have been detected by gaps in dust clouds, where they have swept paths clear. A few have been directly observed, though those are mostly extra-solar planets that have escaped their original system.

With the exception of the one rock planet observed, ALL are gas giants and virtually all many times larger than all the Gas Giants in our own solar system combined. We are NOT talking something the size of Venus, here, we are talking something closer in size to our own sun. This does make a bit of a difference.

To directly observe a planet the size of Earth at a resolution of 1 pixel at a distance of 100 light-years would require a radio telescope with a 1 Km diameter. The proposed Km radio telescope array would do this. Nobody has such a telescope (yet) so nobody is making this sort of claim (yet). But it could be done, it has been designed and (last I heard) it was being built. Once it is finished, planetary discoveries will be made much more rapidly and much more reliably.

It is unlikely to happen in my lifetime, but such an array, in space, would be able to scan a lot of absorbtion frequencies, allowing you to not only detect such a planet, but know the composition of the atmosphere as well. A 1 mile diameter array in space would give you 6.25 pixels-worth of data - certainly enough to detect the existance of weather patterns and possibly enough to detect large moons (provided they are radio objects).

Re:Uhh...

[syntaxglitch]

Actually, it is somewhat surprising that a multi-star system would have a significant planet-forming debris cloud. Orbital mechanics tend to be relatively unstable in multi-star systems, so it's considerably more likely that the dust and debris would end up in unstable orbits and fall into one of the stars, instead of clumping up into a planet with a stable orbit. The fact that a planet can actually have a stable orbit in a system with three stars is actually somewhat surprising to me.

As for the system being thrown together after forming seperately, that's highly unlikely. First of all, space is mostly... well, space. The chances against two star systems colliding at all, nevermind doing so in a way that forms a stable three-star system are, no pun intended, astronomical. Even if a stable three-star configuration formed, it's even more likely that the sudden change in orbital dynamics would promptly eject the planet from the system (not hard to do--actually, if memory serves me, Mercury is in the process of being very slowly ejected from our own solar system. The sun will probably die first, though).

So, yes, lots of things could have happened... most of them probably even more fantastically implausible than the system forming as-is.

Nightfall, the movie (late 1980's)

[phlamingo]

And even worse was a movie based roughly on the ideas in the story. I walked out of the theatre after about fifteen minutes. David Birney (almost as talentless as a Baldwin) as some kind of weird priest, using a hawk to blind a pretty volunteer so she could understand the coming darkness. Or something. I can't remember if Asimov was still alive at the time, but if he was, I suspect this movie killed him. Bleh.

Re:Like Tatooine?

[Justin205]

I don't think that means anything bad, actually...

More info here [security-forums.com].

From reading that, I'm guessing the page just has a really long perl filename accessed from, perhaps, the ad script or similar.

Re:The effects of 3 suns

[dubbreak]

which makes me glad we only have one moon. I can barely deal with each woman in my life having one cycle a month.

More information from Nasa

[dibbe]

More details here: http://planetquest.jpl.nasa.gov/news/7_13_images.h tml [nasa.gov]. Nice animations too.

Re:The effects of 3 suns

[imsabbel]

Well, i answer your first point: Yes, a moon as large as earths (epesially the mass ratio) is very rare (not unheard of, but very rare). Because in self-gravitating systems, the only reason for bodies forming outside the centre is conservation of angular momentum, which goes with m*r^2*omega, which means that a rather small plannet suffices if its only far enough away: look at our solar system: 99.9% of the mass is in the sun, but >99% of the angular momentum is in the planets).
Our earth-moon system is very imbalanced (which is thought to be a result form a collision with an external body), so it should be rare.

about the second one: i dont think we know enough about how intelligent life starts to make ANY kind of guess here, but i dont see how a moon should be required for the basic evolution... The only point thinkable were that tides helped in the primordial phase, but its not like we wouldnt have tides without the moon, the sun alone would be good enough for small ones, too.

Well, the third point: You can have an eclipse :) (This is acutally quite rare, because you need a rather big&close moon).

Re:No

[Anonymous Coward]

The fact that the planet is in a close circular orbit means that it must have lost angular momentum by interacting with the accretion disc from which the star formed. Therefore the two must have formed together. If, however unlikely a star managed to capture a free-drifting planet, it would surely be into an extremely elliptical orbit. This is good enough evidence for me to suggest that planets can form in triple systems.