[Mesa-users] New to MESA need a bit of understanding

[Warrick Ball]

Hi Nick,

I'll borrow from your reply to Rob but it'll help us to know more 
precisely what you're trying to do and what you've tried.  I've toyed with 
"supermassive" stellar models before though it's been a while since I last 
tried anything and my knowledge of the literature is probably hazy and 
outdated.

In your reply to Rob, you wrote:

> From the work I’m following with the initial conditions in the controls 
> I’m trying to get the stars to reach 10^4 solar masses.

Which "work"?  A paper?  Or someone else's inlist?  If so, whose?

In terms of your timestep problem, have you looked at the output of what 
your star is doing?  I tried the inlist you sent (2 Msun accreting at 
0.001 Msun/yr) and you might find it interesting to plot radius as a 
function of stellar age.  Also, have you searched the mailing list for 
anything about supermassive stars?  If so, what did you find?

When asking for help on technical forums, you're more likely to get help 
if you can demonstrate that you've already tried to help yourself. 
Hopefully we'll be able to help you learn how to better diagnose the 
problem and work out a solution that works for your scientific goals.

Cheers,
Warrick


------------
Warrick Ball
Postdoc, School of Physics and Astronomy
University of Birmingham, Edgbaston, Birmingham B15 2TT
W.H.Ball at bham.ac.uk
+44 (0)121 414 4552


On Mon, 12 Aug 2019, mesa-users at lists.mesastar.org wrote:

> Hi,
> Im trying to use the create pre main sequence model along with accretion controls to take a star and make it super massive. Im using specific accretion rates in my runs and my issue occurs with each
> accretion rate. Whenever I initiate the run, the star accretes matter until a certain mass (different for each rate) until it stops and prints min timestep error. If I reduce the min timestep in controls it
> gets to the same mass as before but runs for longer on that mass, without accreting any futher, then finishes with the same error message (even at very small min timestep values). Ive tried to set the max
> mass to no limit in the controls but this hasnt helped either.
> 
> I am not sure how the timestep works with this model and why it accretes to a specific mass everytime reguardless of what time controls I add to the inlist. If anyone could explain or help me understand what
> I am doing wrong, that would be much appreciated.
> 
> Thanks
> Nick
> 
> OS: Linux distro, Pop OS
> MESA-r17701
> SDK: I downloaded the may 3 2019 version 
> 
>