[mesa-users] A common stellar-structure myth

[Craig Wheeler]

Alex's stars probably are dominated by electron scattering,
at solar the opacity may be more Kramers...

Craig


On 8/30/16 7:20 PM, RICHARD H D TOWNSEND wrote:
> Hi Alexander —
>
> Interesting! I wonder whether this is a result of degeneracy behaving differently in the Pop I vs Pop III cases. What initial metallicity did you assume — zero, or something small?
>
> cheers,
>
> Rich
>
>> On Aug 30, 2016, at 7:12 PM, Alexander Heger <alexander.heger at monash.edu> wrote:
>>
>> Dear Richard,
>>
>> I just looked at two stars, admittedly Pop III stars, and those, middle of H burn, pressure is 10x higher in 10 M_sun star compare to the 1 M_sun star.  Both half way through H burn.
>>
>> Maybe an interesting difference to Pop I.  And related to the shape of the curve in Ibeling & Duligur (2013).
>>
>> Never mind, gravitational acceleration is zero in the centre of both stars.
>>
>> -Alexander
>>
>> On 31 August 2016 at 09:56, RICHARD H D TOWNSEND <townsend at astro.wisc.edu> wrote:
>> Hi Alex —
>>
>> In the context of an entry-level astronomy textbook, I think ‘gravity’ is intended to reference acceleration (which students have every-day experience of) rather than potential (which they don’t).
>>
>> Regarding pressures — as you can see from the plot below, the pressure at the center of the massive star is about 0.5 dex smaller than that at the center of the solar-mass star. So, comparing pressures doesn’t help here.
>>
>> Rich
>>
>>
>>
>>
>> -- 
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-- 
J. Craig Wheeler
Samuel T. and Fern Yanagisawa Regents Professor of Astronomy
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