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13-Billion-Year-Old Alien Worlds Discovered
astroengine writes "Two exoplanets have been discovered by scientists at the Max-Planck Institute for Astronomy orbiting the star HIP 11952. But according to conventional thinking, these worlds shouldn't exist. You see, HIP 11952 is a 'metal-poor star and planetary formation is hindered around stars with low metallicity (PDF). This isn't the only thing; as metal-poor stars were the first stars to form when the Universe was very young, these two worlds also formed around the same time. They are therefore the most ancient exoplanets discovered to date."
"Planets form around sun" certainly was news 13 billion years ago, it just took this long to reach Slashdot's front page.
Blank until
Except when the ladies ask you that, you say "My love for you".
You are welcome.
Well, they're only 375 light-years away, so I'd say that if they had managed to exist for 13 000 000 000 years, they likelihood of them disappearing in the last 375 is pretty low. My bet is on "are".
And the worms ate into his brain.
time is not an illusion at all, it is the increase in entropy of the structures of the visible universe, it is a non-conserved state function
I am astounded by the amount of rhetoric and vitriol that surrounds astronomical discoveries. Whether or not they are correct, the truth boils down to: we don't have shit for current time observations of anything in the universe. I truly believe that we are on the right path, and models fit observation, but why get so skeptical about everything? By the time we all die, the universe will basically be in the same state. Let's enjoy the limits of our observation, explore and expand them, and then maybe one of our lineage will be able to explore it.
Koalas. They're telepathic. Plus, they control the weather. -Margaret
http://en.wikipedia.org/wiki/Red_dwarf#Description_and_characteristics
It's possible to have stars that can fuse material for as long as 10 trillion years. Yes, T-T-T-Trillion.
The articles I looked at regarding this planet though make no mention to what class of star they're orbiting, so YMMV.
Can a star really last for 13-billion year and not running out of fuel?
Yes. Our own star is about 5 billion years, and probably only halfway through its life cycle.
Just like with dogs, the smaller ones live longer. Red dwarfs are expected to live for thousands of times the current age of the universe, and simply peter out as they exhaust their fuel, burning it slower and slower, but never having the gravity to cause helium fusion.
Actually, it's unknown what it was like before the big bang.
Like the parent said, time itself did not exist until the big bang, therefor, there is no "before" the big bang. There is no such thing as before time, just as there is no such thing as negative mass or negative distance.
There is no "I disagree" mod for a reason. Flamebait, Troll, and Overrated are not substitutes.
Didn't get one thing: the article says the star is 13 billions yo, but it's 375 ly from our solar system.
I always have thought that distance meant age. Which other technique there is to tell a star's age?
Distance is... well, distance. The number of light years something is away means that we are looking at what happened that many years ago. In this case, what we see happened 375 years ago. It has nothing to do with the age of the object. However, if we see a galaxy 13 billion light years away, we know that the galaxy is 13 billion years old since nothing is that much older, provided it still exists. We don't really know as we would be seeing it as it existed 13 billion years ago. To see how it looks today, we'll have to wait another 13+ billion years and look at it again.
As for judging the age of a star, I'll take a stab at it, although IANAA. If I recall correctly, there are several methods used to judge the age of a star. We know by looking at what the star is composed of which developmental stage it is currently at. We know by its size and energy output how fast it is burning its fuel. So, if we see a large, bright, hydrogen star, we know that it is fairly young since large hydrogen stars don't last long. We can be more accurate by figuring out how fast it burns its fuel and how much it has left (helium to hydrogen ratio). If we see that it is composed mostly of helium, we know that it is in its second stage. We can judge by its size how long it was in its hydrogen stage before it fused it all to helium.
I have not RTFA, but I believe they are judging that this star was one of the first out of gate judging by how much metal it has in its core, meaning that it is very, very old.
Take with salt. Like I said, I'm no astrophysicist.
What I don't understand is how do the scientist know that these were not rogue planets, formed much later and then became trapped by the star's gravity. Just because a star has planets orbiting it, doesn't mean that those planets formed along with the star.
There is no "I disagree" mod for a reason. Flamebait, Troll, and Overrated are not substitutes.
13.75 +/- 0.11 billion years
(The same age as the universe)
time has a very concise and hard definition, much more so than this word "mind" you invoke with your vague and nebulous words. Reality is not an illusion; jump from the roof of a skyscraper to the street, and even though you convince yourself some other event is happening, you will die when from the sudden stop regardless. Reality trumps all, and time is a very real component of reality.
Early supernovae wouldn't help - the star is formed from the same material as the planets would, and the star demonstrably has almost no metals. Early supernovae would just mean that this star didn't exist (in its current chemistry), or that it is even younger than currently estimated, so as to form before the supernovae.
Interstellar captures are very difficult. Generally speaking, you need three gravitationally interacting bodies to allow a capture, as you need one to carry away some energy. Basically this requires the wanderer planet to turn up just when the star is passing close to another one, and even then to get really lucky. (Most often it is the lowest mass object of the three which gains energy, but we need the planet to lose energy.) Another possibility is you could lose that energy through tidal losses, but this requires the wanderer has very small positive energy initially, and passes very close to the star. Either way, the odds of such a capture are very low.
In addition, we have the fact that this star has two planets, which makes the odds against capture polynomially* smaller. Finally, if two planets were captured, we'd expect them to have different orbital planes. Given that they were detected by the 'wobble' method, I'd expect this could be measured, and would be mentioned if it had been so. However I can't promise that there aren't gravitational interactions which would bring the orbital planes into alignment over 13Gyr. Captures would also initially have highly elliptical orbits, which again the wobble method should notice, and again I don't know if 13Gyr is long enough to circularize the orbits by tidal effects or planet-planet interactions.
* This word brought to you by the Committee Against The Misuse Of The Word 'Exponentially'
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
time is not an illusion at all, it is the increase in entropy of the structures of the visible universe, it is a non-conserved state function
So, does time run backward in your freezer, and faster than normal around it?
Sheesh, evil *and* a jerk. -- Jade
They're only 375 light years away.
Maybe the light took the scenic route.
Sheesh, evil *and* a jerk. -- Jade
Time is an illusion. Lunchtime, doubly so.
Being stoned doesn't make you more insightful than anyone else. It just makes you stoned.
http://alternatives.rzero.com/
Nothing is "ageless".
How old is time itself?
I don't think that's a well-formed question. It's like asking "how long is distance?".
Sheesh, evil *and* a jerk. -- Jade
another idiom busted
It is difficult for a body not already in orbit around a star to be captured by it unless there is a third body or something else (dust cloud, etc.) nearby to take away some of the kinetic/potential energy involved. If there is no third body then by a conservation of energy argument -- the small body falls toward the star, faster as it gets closer then slingshots around and back into interstellar space. Even if there are "third bodies" around it is just as likely they will transfer energy to the interstellar visitor and send it out with more speed than it came in with. Similar thing happens with the solar system comets -- they are technically in orbit around the sun way, way out there but occasionally one gets perturbed and comes in close -- unless it gets further perturbed by a planet it will fly a practically parabolic trajectory and go right back out to the far edges of the solar system.
We can test for changing fundamental constant. IIRC, we have observed the decay of a shortlived (in the order of days) isotope in a distant supernova. We have confirmed that the half-life is the same as is observed now. Half-lifes are quite complex, being affected by most of the fundamental constants. Either the constants are nearly unchanged since these supernova exploded, or they have changed in a way to exactly cancel out the effects of each of them on the half-life. Furthermore, the Okla natural nuclear reactor has a distribution of daughter nuclei we would expect to find today. Again, either the fundamental constants are unchanged, or their change is fine-tuned to give the correct answer. Applying Occams razor, the fine-tuning explanation is out until we find evidence that supports it and not the unchanging natural constants hypothesis.
I always tell them "life without you is like a broken pencil!". If she's a Blackadder Fan she will understand :)
no, the refrigerator does work moving heat to the outside in time with some of that energy thereafter unavailable to do work, increasing the overall entropy of the universe even though causing a local decrease of entropy inside
And that folks, is the definition of a refrigerator here on Slashdot! Still wonder why you don't have any gfs? Seriously though, this is why I love /.