Talk:Red dwarf
It seems to me that if we have not observed any red dwarf stars with zero metal content, then we have indeed observed red dwarf stars that have moved off the main sequence and we are still left with the puzzle of determining the precise age of the universe. About all we can say for certain is that the universe should be much older than the estimates that are popular at the moment.
The reason I bring this up is because I cannot imagine how you find a red dwarf that has gone cold. It seems unlikely that they would become white dwarfs harboring degenerate matter. This is a case of an absence of something indicating a condition we have failed to properly conisider.
Giant dwarfs
I disagree with this statement: Red dwarfs never initiate helium fusion and so cannot become red giants Red giants, at least as expected with Sun-like stars, occur before the initiation of helium fusion, with shell hydrogen fusion. Although it might take more-then-the-current-age-of-the-Universe for red dwarfs to reach the point of having an inert helium core, I could imagine this state of affairs, at least with the bigger end of red dwarfs. Does anyone have any better information? Joffan 19:02, 16 September 2005 (UTC)
Population III stars.
Stars of extremely high mass that burned out quickly, by cosmological standards, and thereby created all the metals needed for the current crop of Population II and Population I stars. Shouldn't this have left us with a very high number of neutron stars, magnetars, and black holes? Wouldn't the consequences of having a large number of such objects around be rather serious?
Here, I am not criticizing Wikipedia as this seems to be an accurate exposition of current theory. Nevertheless, I do have serious misgivings about the theory. Granted, Astronomers, Astrophysicists, and Comologists need a theory to work with and from, but they seem terribly cocksure at times.
Quoting the article on Pop III stars here, because I cannot get the talk tab to work on that article:
"If these stars were able to form properly, their lifespan would be extremely short, certainly less than one million years. As they can no longer form today, viewing one would require us to look to the very edges of the observable universe. (Since the time it takes light to reach Earth from great distances is extremely long, it is possile to see "back in time" by looking farther away.) Seeing this distance while still being able to resolve a star could prove difficult even for the James Webb Space Telescope."
If the theory concerning these putative stars is in any way correct, then JWST should be able to view entire galaxies of such stars, yes? The spectra of nearly all the stars should all be very nearly the same, depending upon the age of the putative galaxies of Pop III stars. In fact I would expect the spectra of such young galaxies to fall into "bins" according to their ages. A galaxy only one million years old should be easily distinguishable from one that is slightly older than one million years and so on until all the Pop III stars have had time to burn out. Metalicity galaxy wide should increase with age in almost stair-step fashion.
It amazes me, by the way, that something around one percent or less of elements heavier than helium can have such profound effects on stellar size. Current counts suggest that the overwhelming majority of Pop II and Pop I stars are K to M class dwarfs. Why the anticipated paucity of such stars in Pop III? Simply because we have not found any such stars that have turned off the main sequence?
Personally, I think it is more likely that we have not found them because they are dim and we have not devoted enough instrument time to look for them. But, then again, perhaps the black holes gobbled them up.
70.116.68.198 06:56, 1 January 2006 (UTC)Don Granberry.
More on Population III Stars
Here is a very useful link:
http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v540n1/50350/50350.html
Somewhere along the way, their simulation runs must have butted heads with Xeno of Elea. They assume the existence of "dark matter" and a considerably less than homogenous cloud structure in the "early universe."
There is no suggestion that any non-linear, self-iterative processes were considered. Such large clouds of gasses would necessarily be affected by such processes.
The upshot is that we appear to be placing a wee bit too much faith in a computing model limited by computing resources, particularly when it is claimed that only very large stars, something greater than 30 solar masses, were made during this period of cosmological history.
While this IS a good working theory on which to foot further investigations, the investigators seem to be entirely too eager to comply with pre-conceived notions. In court they would be accused of "assuming facts not in evidence." Rather than being an effort to discover the nature of stars that formed during the early periods of the universe, assuming the universe had an "early period", this seems to be an attempt to shore up a problem ridden model of the universe.
The current cosmological model may one day be shown to be correct, but dogmatic adherence to it prior to such a demonstration strikes me as being a very poor procedure. While a sincere search for very old red dwarfs or K stars of Population III would arduous, it should nevertheless be carried out.
70.116.68.198 17:29, 1 January 2006 (UTC)Don Granberry