[mesa-users] Mass Transfer + Rotation Problems

[Bill Paxton]

Hi Pablo,

On Mar 3, 2013, at 8:05 AM, Pablo Marchant wrote:

> Ok, saved a model of the accretor for the binary run, just before mass transfer, to experiment with it with single star mesa.
> 
> Attached is the model star with the inlist I'm using to test it. For mass_change = 1d-5 the model has problems converging and ends up with very small timesteps right away. Slightly smaller mass_change can cause the model to behave at the first timesteps, but end up in the same situation.

I'll give it a try and let you know if I find anything interesting.

> 
> Just to note, this also seems to happen with mass loss, though things start getting messy at around mass_change = -1d-4.

Hmm.   We've done lots of rotating stars with mass loss greater than that.  But each case is different it seems.

> 
> The value 1d-5 is actually around the same value that the implicit scheme attempts before ending up with tiny timesteps, and it's not very high, I would actually expect it to rise significantly more than that.
> 
> I'm certainly interested in digging into the mass adjustment routines and how it deals with angular momentum, as I'm starting to check how to implement the missing features regarding rotation into binary MESA.

Section B6 of the new instrument paper has an overview you should read if you haven't already.

Note that we don't yet do anything fancy about angular momentum of accreted material; that will need to change.

Cheers,
Bill