Stellar Re-count

[rommel543]

There may be more out there then previously thought.


http://www.sciencedaily.com/releases...0819145846.htm

...the universe was thought to create stars in specific bundles. In other words, the proportion of small to big stars was thought to be fixed.For every star 20 or more times as massive as the sun, for example, there should be 500 stars with the sun's mass or less.

This belief, based on years of research, has been tipped on its side with new data from NASA's Galaxy Evolution Explorer. The ultraviolet telescope has found proof that small stars come in even bigger bundles than previously believed; for example, in some places in the cosmos, about 2,000 low-mass stars may form for each massive star. The little stars were there all along but masked by massive, brighter stars.

...

[cosmocrazy]

so how does this evidence effect the expected mass of the galaxies and therefore the mass of the universe? anything significant? i would expect to see smaller stars far more common than massive ones since the smaller ones have a much longer life span anyway.

[rommel543]

Well the calculated mass of galaxies was based on the idea that there was a 500 to 1 ratio of smaller stars (1 solar mass or less) to larger stars (~20 solar masses). So in a hypothetical galaxy say they counted 1 million large stars (~20 solar masses or bigger), they would then calculate that there were 500 million stars that they couldn't see (1 solar mass or less). Now with the new observations be the Galaxy Evolution Explorer, they found that there would be 2 billion non-visible stars. I would think that would be a significant increase in mass.

I am wondering if this increase also would affect the calculated number of brown dwarfs? I'm pretty sure that they have some calculation that estimates the number of brown dwarfs in relation to regular stars. If there is this would also increase the numbers there as well.

[trinitree88]

Well the calculated mass of galaxies was based on the idea that there was a 500 to 1 ratio of smaller stars (1 solar mass or less) to larger stars (~20 solar masses). So in a hypothetical galaxy say they counted 1 million large stars (~20 solar masses or bigger), they would then calculate that there were 500 million stars that they couldn't see (1 solar mass or less). Now with the new observations be the Galaxy Evolution Explorer, they found that there would be 2 billion non-visible stars. I would think that would be a significant increase in mass.

I am wondering if this increase also would affect the calculated number of brown dwarfs? I'm pretty sure that they have some calculation that estimates the number of brown dwarfs in relation to regular stars. If there is this would also increase the numbers there as well.

rommel. Oops! from the Desert Fox... pete

[Weakly Interacting MP]

Well the calculated mass of galaxies was based on the idea that there was a 500 to 1 ratio of smaller stars (1 solar mass or less) to larger stars (~20 solar masses).

Actually, I don't think this is quite right. The mass of a galaxy is determined by it's rotational speed and luminosity. Check this out:

http://zebu.uoregon.edu/~soper/Mass/galaxymass.html