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Star Near Our Solar System May Be the Oldest Known


Sheila
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That is very interesting. That means it was forming right at the very begining since the Universe has been calculated as 13.77 Billion years old. Hardly seems long enough to bake a cake in the grand scheme of things.


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Yes, although let's not forget our Sun has a life expectancy on around 10 Billion years and is but a wimp in comparison to many stars. The amazing part of this star is that it is so old already which means it defies the model we have so far considered correct for star formation in the very early days of the Universe.


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From what I have read, if a star has no elements other than hydrogen and helium, it burns very stable and long. But if it has been seeded with any other elements, possibly the remnants of nearby supernova, then they burn at an accelerated rated, particularly, once Carbon is involved. 


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It's more to do with the mass of the star. A very large star with high luminance will burn "fuel" at a much faster rate than a smaller star with less luminance.

 

Hydrogen fusion burning is one of the most efficient ways for a star to make the heat and luminosity required to remain stable. Iron fusion is one of the most in-efficient ways, a star will burn all of the Iron "fuel" very fast indeed, I forget now, but it is a fraction of the time that a Hydrogen burning star is in that stage.

 

From the following http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit2/

 

 

Main Sequence Lifetime
 

The Nuclear Timescale above depends on the Mass (M)
and Luminosity (L). But, we know from the Mass-Luminosity Relation for Main Sequence
Stars that

L = M4
 

If we combine this with the formula for the Nuclear
Timescale
, we get the Main Sequence Lifetime:

tMS ~ 1 / M3
 

The consequence is that the M-S lifetime is strongly dependent on the
Mass of the star, in the sense that:

High-Mass M-S Stars have short M-S lifetimes Low-Mass M-S Stars have long M-S lifetimes

Examples:

Sun: M = 1 Msun, and tMS = 10 Gyr



 

Massive Star (10 Msun): tMS = 10 Gyr / (10 Msun)3 = 10 Million Years
 

 

Low-Mass Star (0.1 Msun): tMS = 10 Gyr / (0.1 Msun)3 = 10 Trillion Years
 

Edited by Perkil8r
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