Zam-Zam
Senator
It was fun while it lasted.......
The Stars Are Beginning To Go Out…
They really are.
The universe is apparently well past its prime in terms of making stars, and what new ones are being made now across the cosmos will never amount to more than a few percent on top of the numbers already come and gone.
This is the rather disquieting conclusion of a new and significant study of the rate at which stars have been produced through cosmic time.
Sobral and colleagues recently published the results of a series of ‘snapshots’ made of galaxies busily making stars at different epochs, from about 4 billion years ago (around the time of Earth’s formation) all the way back to nearly 11 billion years ago. This is no simple task, some of the world’s largest and most sensitive telescopes had to be employed.
By observing light at very specific frequencies (corresponding to emission from warm hydrogen atoms – see the note below) they are able to gauge the actual rate at which new stars are condensing out of thick nebular material in a few thousand galactic systems. This yields some very robust statistics on the global changes in the numbers of new stars being made as the universe ages.
The main conclusions come in two parts. First, 95% of all the stars we see around us today were formed during the past 11 billion years, and about half of these were formed between roughly 11 and 8 billion years ago in a flurry of activity. But the real shocker is that the rate at which new stars are being produced in galaxies today is barely 3% of the rate back 11 billion years ago, and declining. This indicates that unless our universe finds a second wind (which is unlikely) it will only ever manage to produce about 5% more stars than exist at this very moment.
This is, quite literally, the beginning of the end.
Complete text: http://blogs.scientificamerican.com/life-unbounded/2012/11/19/the-stars-are-beginning-to-go-out/
The Stars Are Beginning To Go Out…
They really are.
The universe is apparently well past its prime in terms of making stars, and what new ones are being made now across the cosmos will never amount to more than a few percent on top of the numbers already come and gone.
This is the rather disquieting conclusion of a new and significant study of the rate at which stars have been produced through cosmic time.
Sobral and colleagues recently published the results of a series of ‘snapshots’ made of galaxies busily making stars at different epochs, from about 4 billion years ago (around the time of Earth’s formation) all the way back to nearly 11 billion years ago. This is no simple task, some of the world’s largest and most sensitive telescopes had to be employed.
By observing light at very specific frequencies (corresponding to emission from warm hydrogen atoms – see the note below) they are able to gauge the actual rate at which new stars are condensing out of thick nebular material in a few thousand galactic systems. This yields some very robust statistics on the global changes in the numbers of new stars being made as the universe ages.
The main conclusions come in two parts. First, 95% of all the stars we see around us today were formed during the past 11 billion years, and about half of these were formed between roughly 11 and 8 billion years ago in a flurry of activity. But the real shocker is that the rate at which new stars are being produced in galaxies today is barely 3% of the rate back 11 billion years ago, and declining. This indicates that unless our universe finds a second wind (which is unlikely) it will only ever manage to produce about 5% more stars than exist at this very moment.
This is, quite literally, the beginning of the end.
Complete text: http://blogs.scientificamerican.com/life-unbounded/2012/11/19/the-stars-are-beginning-to-go-out/