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Fraser
2007-May-11, 06:09 PM
The Universe is thought to be 13.7 billion years old. So it was quite a surprise when astronomers turned up a star that's 13.2 billion years old. That means it formed only a few hundred million years after the Big Bang. ...

Read the full blog entry (http://www.universetoday.com/2007/05/11/a-star-as-old-as-the-universe/)

pantzov
2007-May-12, 09:59 AM
perhaps they may soon be forced yet again to reexamine just how old they think that universe really is. i love it.

Blob
2007-May-12, 10:24 AM
Hum,
perhaps,
but i read the instructions that came with it; and i find that it is impossible to adjust the age by any great degree.
Between 12 billion to 15 billion years is a reasonable guess; with the latest WMAP data indicating that it is perhaps 13.7 ± 0.2 billion years old.

http://map.gsfc.nasa.gov/m_uni/uni_101age.html
http://en.wikipedia.org/wiki/Age_of_the_universe

Maddad
2007-May-12, 06:31 PM
The star cannot be a first generation star because it has radioactive elements in it. It has to have been born of the debris of a supernova; there cannot have been enough time in the universe for a lighter mass star to have gone through a planetary nebula stage to produce these elements. Besides which, that could only result in ligher elements anyway, up through iron. There's a slow fusion process that can create them, but not in any useful, measurable quantity.

plancker
2007-May-13, 10:22 AM
The star cannot be a first generation star because it has radioactive elements in it. It has to have been born of the debris of a supernova; there cannot have been enough time in the universe for a lighter mass star to have gone through a planetary nebula stage to produce these elements. Besides which, that could only result in ligher elements anyway, up through iron. There's a slow fusion process that can create them, but not in any useful, measurable quantity.

The original artcle also says "Once the star originally formed, its radioactive elements began to decay". Is this just a mistake? Didn't the radionuclides start to decay as soon as they were formed? Doesn't the radio-dating just tell us when the earlier generation star(s) went supernova and produced these elements? If so, what do we really know about the star's age?

Blob
2007-May-13, 10:46 AM
Hum,
well spotted.


Didn't the radionuclides start to decay as soon as they were formed?

This would contribute to the plus or minus error in the stars age....

General Note: star formation, death, nebula contraction etc can all happen in millions of years; the age of the star and the age of the universe is measured billions (thousands of millions) of years...think centimetres and kilometres...

GOURDHEAD
2007-May-13, 12:39 PM
Just before, during, or immediately following the "range of events" marked by what we now observe as the CMB radiation, there could have been a "rash" of hyper-massive stars formed in the much more mass dense environment which led to a proliferation of supernovae which seeded the population of stars forming soon thereafter with the higher mass elements. Have we observed evidence to the contrary other than the low metallicity of many of the "first generation" stars?


Quoted from wikipedia: Eventually, the universe cooled sufficiently that protons and electrons could combine to form neutral hydrogen. This was thought to occur roughly 400,000 years after the Big Bang when the universe was about one eleven hundredth its present size. Cosmic microwave background photons interact very weakly with neutral hydrogen.

The behavior of CMB photons moving through the early universe is analogous to the propagation of optical light through the Earth's atmosphere. Water droplets in a cloud are very effective at scattering light, while optical light moves freely through clear air. Thus, on a cloudy day, we can look through the air out towards the clouds, but can not see through the opaque clouds. Cosmologists studying the cosmic microwave background radiation can look through much of the universe back to when it was opaque: a view back to 400,000 years after the Big Bang. This “wall of light“ is called the surface of last scattering since it was the last time most of the CMB photons directly scattered off of matter. When we make maps of the temperature of the CMB, we are mapping this surface of last scattering. By the way, if the physical (larger than observable) universe is taken to be 75 billion lightyears in radius, one tenth of that size is 7.5 billion lightyears. Why isn't the generation (or revelation if you prefer) of the radiation that we now observe as the CMB "modulated" by the points in the source being separated by such large distances from each other? How could there have been a surface of last scattering that generated a wall of light that has become the CMB? Are there features in the CMB that reveal the size of the time interval over which neutral hydrogen (deionization) became sufficiently prevalent to initiate what we now call the CMB? Was it a few seconds, hours, days, years, thousands of years?

Nick4
2007-Jun-07, 01:21 AM
Ok either we are way wrong about the age of the Universe or maybe the star was formed in a special way...maybe the star was born so close to the big bang when there was so much comprest dense matter in a small space that maybe the star picked up alot more matter than it should have to enable it to last as long as it did...or maybe the star isent even there anymore and its just so far away that we are seeing the light that left it when it still was there...interesting.