[mesa-users] solar calibration with Asplund abundances

Aldo Serenelli aldos at ice.csic.es
Tue Jan 14 14:50:39 EST 2014


Jean-Claude, 

regardless of the wrongness of MLT and all other possible sources of errors, your solar calibration should reproduce other solar calibrations, provided the input physics is the same (or very similar). 
Your quoted helium abundance is certainly too high compared to all other solar calibrations in the market that incorporate gravitational settling in the model.

One point is: your accuracy is certainly too low. The three quantities solar models are forced to satisfy are:

L_sun, R_sun, Z/X

and this can be done to parts per 10^5 easily by all codes around. So, your calibration right now is not good. Since L_sun and R_sun are satisfied by construction, so it will be Teff. Keep in mind the Sun evolves very slowly, so a 5% difference in L is actually a very long period of time.

You should therefore check what is causing the difference. Here are some possibilities:

1) improve accuracy
2) is grav. settling included?
3) opacities consistent with assumed (AGSS09) abundance?

You won't get Rcz right, of course, but your results should be overall much more consistent with published literature.

Aldo

On 14 Jan, 2014, at 5:37 PM, Jean-Claude Passy wrote:

> Hi all,
> 
> I was wondering if anyone had tried a solar calibration but with the Asplund abundances. I gave it a try and found the following accuracies:
> 
> 1% in Teff,
> 5% in L,
> 2% in Rcz.
> 
> Comparing with Serenelli et al. (2009):
> http://esoads.eso.org/abs/2009ApJ...705L.123S
> 
> these results are consistent in terms of Rcz, and better regarding the He surface abundances (here Ysurf = 0.2477). I used MESA version 5595 (inlists and output attached).
> 
> Has anybody tried to do the same thing and found better accuracies?
> 
> Cheers,
> 
> JC
> 
> <inlist_astero_search_controls3>
> <inlist_solar3>
> <sample_0001.data3>
> 
> 
> 
> 
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