Wednesday, March 02, 2011

Like grains of sand...these are the red dwarfs in our skies...

Dan sends in an article by the "amateur naturalist" Dana Wilde commenting on how our view of the universe has changed in less than a hundred years. I just can't resist beating around some of the ideas that Wilde brings up.

Who doesn't remember Carl Sagan's Cosmos? Sagan would often make a pronouncement of scale that was totally astounding. I can clearly remember Sagan in the early 80s proclaiming that there are more stars than grains of sand on the beaches of Earth. Now one astronomer trying to put a number to Sagan's pronouncement estimated that there are about 2000 billion billion grains of sand on Earth. That's a serious haul of stars by anyone's estimate.

In amongst the visible class of stars are, for lack of a better label, ghost stars. Stars so small, dim and cool as to be all but invisible under most detection methods. Red Dwarf stars and no one could come up with a reasonable amount of these "ghost stars'. Recently Yale astronomers determined that there are many more of red Dwarf stars than anyone thought possible. Yale astronomers detected the light from red dwarf stars in the spectra of large elliptical galaxies and from this determined that red dwarfs account for around 60% of the mass (star mass) of those galaxies. That is triple what was previously thought to exist!

What is even wilder about red dwarfs is just how slow they age. Because they are relatively cool and very small these stars burn their fuel very slowly. So slowly in fact that the present universe is not old enough for red dwarf stars to grow "old". Which when you come to think about it means that virtually every red dwarf that present at creation of the universe, is still burning 13+ billion years later!

Bangor Daily News article


Blizno said...

Of course there were no stars at the "creation of the universe". There was no matter. There was only a raging Hell. Matter would precipitate out later and the first stars would form much, much later.

I enjoyed this article, especially the finding that red and darker stars may be far more numerous than previously thought and many stars as old as stars can possibly be may still be slowly burning through their birth-fuel.

Beam Me Up said...

Yeah Blizno... every time I wrote that line it sounded awkward. The whole idea was to point out that since the first dwarf reds came into being, they are most likely still here and burning ever so dim.

I think to that you make a valid point with the dim red and darker stars and if we stop for a second it might make more sense to look at these unseen stars for a lot of the missing mass in the universe.