Astronomers Discover Oldest Star in the Universe

[StewShearerOld]

Astronomers Discover Oldest Star in the Universe

Astronomers from the Australian National University have discovered a 13.7 billion year old "first star" born in the early days of the Big Bang.

The sun is kind of a big deal. Granted, anyone who's ever been able to see should know that, but it can still be easy to forget that in addition to giving us light, warmth and romantic sunsets, it's also a giant, ancient fireball around which everything in our solar system quite literally revolves. That being the case, as far as stars go, our sun isn't really all that old. Granted, 4.6 billion years is a lot to us mere mortals, but on the cosmic scale it's only middle-aged.

That being the case, astronomers have apparently discovered a star that makes our sun look young in comparison. The star in question is 13.7 billion years old and, according to its discoverers at the Australian National University Research School of Astronomy and Astrophysics, is the oldest known star in the universe. The team found the star using ANU's Skymapper telescope at the Siding Spring Observatory. The telescope has a "unique" ability to "find stars with low iron from their color." This comes in handy for stars such as this one which the astronomers believe to be a "first star" originating from the earliest days of the Big Bang itself.

According to Dr. Stefan Keller, the discovery of this ancient star has yielded some new and valuable details about the early formation of the universe. Whereas past theories had surmised that older stars died in massive explosions polluting vast tracts of space, it would now seem that "the primordial star's supernova was of surprisingly low energy" and that the star itself transformed into a black hole that consumed the bulk of its left over materials.

Source: <a href=http://www.sciencedaily.com/releases/2014/02/140209200836.htm>Science Daily



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[DasDestroyer]

Wait, so did they find the star itself or the black hole it left behind?
Also I recall that stars start to lose energy once they start to fuse iron, so wouldn't an older star have more iron?

 

[AstaresPanda]

also might the star not be dead by now ? light travel and all that

 

[DasDestroyer]

Wait, so did they find the star itself or the black hole it left behind?
Also I recall that stars start to lose energy once they start to fuse iron, so wouldn't an older star have more iron?

Generation I stars contain only hydrogen, because there were no prior stars to create the heavier elements. Generation II stars, such as our sun, contain more of a mix. Generation I stars also tend to be huge, hot, and short-lived.

What we're looking at right now is the light from a star 13.7 billion light years away. Meaning, the light we're seeing left the star 13.7 billion years ago. Which means that light was generated from one of the first stars after the Big Bang.

Oh, so they saw a "first star" when it was young, really far away. Okay, that makes sense, I thought they'd discovered an ancient star that was somewhat closer, and possibly even still burning, which would have been a much more amazing discovery.

Edit: Actually, I just read the article and the star in question is only 6000 light years away, and most likely still burning.
In that case I guess the reason why it has so little iron is because it would have to be a tiny star to have survived for so long, and since tiny stars burn really slowly it still hasn't gotten to the point where it produces its own iron.

 

[Pyrian]

...

They looked for stars with low iron.

They found a star with low iron.

From this, they concluded a whole lot of "amazing" things which could just as easily be explained as "if you look at enough stars, you might find a few with low iron entirely coincidentally."

 

[Glaice]

This is rather fascinating to discover, I would not think stars could live this long.

 

[Albino Boo]

...

They looked for stars with low iron.

They found a star with low iron.

From this, they concluded a whole lot of "amazing" things which could just as easily be explained as "if you look at enough stars, you might find a few with low iron entirely coincidentally."

This very low level of iron could not have occurred in later stars. Metals in general and Iron in particular are the products of nuclear fusion and supernovae. Iron is important because all fusion taking place elements with atomic numbers below that of Iron release energy and Iron and above uses energy. This fact means that even long lived early stars would not have significant amounts of iron in them. The death of the early stars would have created large of amounts of iron and spread it across the galaxy. Using spectroscopy iron is good marker for determining the age of stars.

 

[GundamSentinel]

What I get from the article is that they didn't in fact find a star formed right after the Big Bang, but rather one that formed slightly more recently (all relative, but whatever) and gives a good impression of what the Universe looked like before it was formed. Interesting, to be sure, but not really as dramatic as the article makes it out to be.

 

[Pyrian]

This very low level of iron could not have occurred in later stars. ... The death of the early stars would have created large of amounts of iron and spread it across the galaxy.

Galaxies are big and small, there are pristine clouds of hydrogen just floating around out there (by some estimates, MOST of it), some gases mix and others get missed for immense periods of time. Our galaxy in particular is amalgamation of many, some ancient, some recent, some arriving soonish.

I find it completely unsurprising that in a large survey you might find an occasional outlier. We can't just assume because we found an unusual star, that it's formation must've been perfectly ordinary in all other respects. In fact, we might just as well assume the vice versa. And if its formation wasn't particularly ordinary then it wasn't necessarily particularly representative of anything, either. One data point does not form a line, nevermind a complex mosaic. It could've formed from the far edge of a primordial hydrogen cloud slamming into what's now the Milky Way.

And I'm not just saying we don't necessarily know how old it is. They go on from an assumed age to purport assumed other stars with assumed other properties, all to explain a result which could easily be just one of those odd things among a great many odd things that just happen to happen once in awhile when your scale is large enough.

I mean, seriously. Let's accept that it's very old. Does that in turn tell us the composition of ancient supernovae, forming in very much the same time period? I don't see how. The star could've formed out of mostly (entirely?) primordial gas collapsed by a shockwave long before large numbers of supernovae mixed things up. How are they simultaneously assuming that it's old because it's iron is low, and that said low iron is a measurement of the early universe - as opposed to age? The whole thing seems very circular.

 

[Albino Boo]

This very low level of iron could not have occurred in later stars. ... The death of the early stars would have created large of amounts of iron and spread it across the galaxy.

Galaxies are big and small, there are pristine clouds of hydrogen just floating around out there (by some estimates, MOST of it), some gases mix and others get missed for immense periods of time. Our galaxy in particular is amalgamation of many, some ancient, some recent, some arriving soonish.

I find it completely unsurprising that in a large survey you might find an occasional outlier. We can't just assume because we found an unusual star, that it's formation must've been perfectly ordinary in all other respects. In fact, we might just as well assume the vice versa. And if its formation wasn't particularly ordinary then it wasn't necessarily particularly representative of anything, either. One data point does not form a line, nevermind a complex mosaic. It could've formed from the far edge of a primordial hydrogen cloud slamming into what's now the Milky Way.

And I'm not just saying we don't necessarily know how old it is. They go on from an assumed age to purport assumed other stars with assumed other properties, all to explain a result which could easily be just one of those odd things among a great many odd things that just happen to happen once in awhile when your scale is large enough.

I mean, seriously. Let's accept that it's very old. Does that in turn tell us the composition of ancient supernovae, forming in very much the same time period? I don't see how. The star could've formed out of mostly (entirely?) primordial gas collapsed by a shockwave long before large numbers of supernovae mixed things up. How are they simultaneously assuming that it's old because it's iron is low, and that said low iron is a measurement of the early universe - as opposed to age? The whole thing seems very circular.

Its not pristine hydrogen. The early generation stars that are being talked about here collapsed into supermassive black holes. The gas jets given off by the black holes have been observed to actually reach other galaxies. Vast clouds of hydrogen are also from 2 generation supernovas and even the outer layers of red giants disbursing leaving a white dwarf. If the gas was pristine our own sun would not contain iron. These early stars deaths were galaxy wide events.

 

[Requia]

...

They looked for stars with low iron.

They found a star with low iron.

From this, they concluded a whole lot of "amazing" things which could just as easily be explained as "if you look at enough stars, you might find a few with low iron entirely coincidentally."

You do realize it's possible to tell how far away a star is, and that being farther away necessarily makes it older?

 

[Thaluikhain]

You do realize it's possible to tell how far away a star is, and that being farther away necessarily makes it older?

Er, it doesn't...yes, the star has to have existed long enough ago for its light to reach us, but that doesn't mean closer stars can't be older.

 

[Idsertian]

I'm probably going to make a fool of myself here, but I thought that the mere presence of iron in a star's core caused it to go supernova? Wouldn't the conditions elsewhere in the star mean iron can't exist anywhere else but the core? Thus leading to giant space fireworks?

I may have completely the wrong end of the stick here, but that was my understanding of the situation.

 

[DasDestroyer]

I'm probably going to make a fool of myself here, but I thought that the mere presence of iron in a star's core caused it to go supernova? Wouldn't the conditions elsewhere in the star mean iron can't exist anywhere else but the core? Thus leading to giant space fireworks?

I may have completely the wrong end of the stick here, but that was my understanding of the situation.

I'm pretty sure it's only when the only thing the star can produce is iron that a star becomes unstable. Iron in and of itself doesn't do much except apparently change the light slightly, but once a star has fused everything to the point where it starts to fuse iron, it starts to use more energy fusing the iron than the fusion produces, unlike all the lighter elements, and that's what causes the star to become unstable. And only stars that are ~1.4 or more times the mass of the sun go nova, the smaller ones including the sun just become red giants and leave a white dwarf behind. (someone please correct me if I'm wrong!)

 

[Idsertian]

I'm pretty sure it's only when the only thing the star can produce is iron that a star becomes unstable. Iron in and of itself doesn't do much except apparently change the light slightly, but once a star has fused everything to the point where it starts to fuse iron, it starts to use more energy fusing the iron than the fusion produces, unlike all the lighter elements, and that's what causes the star to become unstable. And only stars that are ~1.4 or more times the mass of the sun go nova, the smaller ones including the sun just become red giants and leave a white dwarf behind. (someone please correct me if I'm wrong!)

Ah. That makes sense. As I thought, I didn't have quite the grasp on the subject I thought I did. Thanks for clearing that up. ^^

 

[Evil Smurf]

The universe is only 6000 years old, lies, these "scientists" are filthy liars.

 

[Requia]

You do realize it's possible to tell how far away a star is, and that being farther away necessarily makes it older?

Er, it doesn't...yes, the star has to have existed long enough ago for its light to reach us, but that doesn't mean closer stars can't be older.

Stars that old would necessarily be low mass (high mass stars do not have good lifespans). There's no formation model for a low mass metal-free star, and any star older would necessarily have formed without metals initially.