Oldest Alien Planets Discovered to Date—Born at Dawn of Universe 12.8 billion Years Ago
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March 28, 2012

Oldest Alien Planets Discovered to Date—Born at Dawn of Universe 12.8 billion Years Ago

 

           RG3m0


Two huge Jupiter-sized planets found orbiting a star 375 light-years away, that will soon transform into a red giant (image above), are the oldest alien worlds yet discovered, reported scientists at the Max-Planck Institute for Astronomy in Heidelberg, Germany. "The Milky Way itself was not completely formed yet," said study leader Johny Setiawan. During a recent survey using radial velocity, in which astronomers watch for periodic wobbles in a star's light due to the gravitational tugs of orbiting worlds, Setiawan and colleagues found the signatures of the two planets orbiting the star, dubbed HIP 11952. 

At an estimated age of 12.8 billion years, the host star—and thus the planets—most likely formed at the dawn of the universe, less than a billion years after the big bang.

Based on the team's calculations, one alien planet is almost as massive as Jupiter and completes an orbit in roughly seven days. The other exo planet is nearly three times Jupiter's mass and has an orbital period of nine and a half months.

"Usually planets form just shortly after the star formation," Setiawan said. "Second-generation planets might also form after a star has died, but this is still under debate."

The discovery indicates that planet formation in the early universe was possible despite the fact that stars in existence back then were lacking in elements heavier than hydrogen and helium, which runs counter to a widely accepted theory called the accretion model, which says that heavy elements are needed to form planets. In the case of HIP 11952, "its iron abundance is only about one percent that of our sun," Setiawan said.

The accretion theory has so far been backed up by observations: Most of the planet-harboring stars discovered to date are relatively young and have moderate to high amounts of metals, but Setiawan says that "astronomers may think the accretion model is correct because planet hunters using Kepler Mission data have been targeting mostly young, sunlike stars."

"To verify this issue, it is necessary to do a planet-search survey around [older] metal-poor stars," Setiawan said.

The Daily Galaxy via Astronomy & Astrophysics

Image credit: lcse.umn.edu

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Comments

Interesting. It would seem that terrestrial planets are a relatively new phenomenon within stellar evolution, that is way back then gas giants and superfluid planets were the dominant planetary bodies forming around stars.

Or it may just be that the Universe is a bit older than the tenured idiocracy thinks, that they think they know :-)

Also this 'metal' abundance theory, is just a flimsy theory. May me something to it, but the its workings and exceptions are not known.

So,these are hydrogen/helium gas giants.

p.s.:
Cato, just exactly what science are you practicing? Lol.

I am a voodoo priest :-) My area of expertise is just adept at illuminating the mysteries behind the Big Bang. Trust me :-)

p.s. it is not clear what hey are, perhaps they are composed of light elements only. However so seem the the local giant planets. Whatever passes for science in this instance, seems based on current 'scientific' prejudice.

How does finding gas giants prove anything about whether there was enough metals around? They aren't made of metals.

the Universe is a bit older

The likelihood of these planets forming early are extremely rare. That is why we very rarely find one, but we did. Although it isn't expected that any iron would have formed by then, it is likely that iron bodies that were formed later could have merged, or collided with, the existing rare gas planets. It would seem that 12 billion years would give those planets more than enough opportunity for countless scenarios to occur in their lifetime.

Its the low metal content of the stars that they are talking about. Spectral analysis of the stars light tells them that.
So by inference the planets are metal poor as well. Does that explain it for you Cato?

It's so interesting!!

Cato:

The gas giants of our solar system do not seem to be made of light elements only. If they were, this wouldn't be anything like a significant find. We don't know that this find *is* really all that significant, since we can't yet do a spectroscopic study of the planets themselves, but if Jupiter and beyond were already very low metalicity planets, there wouldn't be any kind of controversy here at all.

Speaking of 'controversy', since you seem to reject the findings of the "tenured idiocracy", how old do you say the universe is, and what methods did you use to come to that conclusion? Destructive criticism is less than worthless if you cannot propose a superior substitute.

John - You comment induced me to re-read the article. They only mentioned the low-iron content of the star, which by inference would apply to the accretion material available for planetary formation. I guess we still have to discover the low end of available heavy materials that will allow planets to form. It will probably be concluded as a rare, but still possible, occurrence.

During the lifetime of a star, it produces heavier elements until it has iron enough to begin its colapse. Since this star is so old, shouldn't it contain higher concentration of heavy elements by now?

Rafael
Its my understanding that (according to theory) smaller stars last the longest. Maybe smaller stars dont have the internal pressure/heat to make heavier elements would be my guess.

Iron is used as a tracer material. It's very easy for us to see in stars, and stars with more/less iron tend to have higher/lower amounts of other materials heavier than hydrogen and helium as well. The article saying that astronomers found that the stars were very low in iron is, to an astronomer, a way of saying that the stars are made of almost nothing other than hydrogen and helium.


Rafael, smartypants:

Stars as small as the sun, or even smaller, cannot make elements heavier than carbon. Even the largest stars, however, which do make iron in their cores, will not get "more iorny" or anything like that over their lifespan. We only see the surfaces of the stars, and so we can only measure the amount of iron (or any other material, for that matter), that happens to be at the stars' surfaces. The heavier elements, like carbon, oxygen, silicon, or iron are produced in the stars CENTRES, though, and those materials stay there until very nearly the end of the stars' lives. We do not see the amount of iron go up as the stars age, regardless of how large or small they may be.

That would be like measuring the size of your kidney stones by looking at the hair on your knuckles.

that is not the oldest planet yet because clster m4 is


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