[Mesa-users] Issue with rotation in MESA r22.11.1

[Matteo Cantiello]

Hi Willie,

It seems like you’re suggesting that the shape of the evolutionary track is
‘odd,’ but I think it’s more accurate to say that it differs from the
PARSEC model. This difference isn’t entirely surprising, as the MESA
calculation reaches critical rotation, while the PARSEC model does not.

There could be a variety of factors contributing to the discrepancy -- such
as differences in initial conditions, the treatment of mixing, or angular
momentum transport -- and it’s difficult to pinpoint the exact cause based
solely on the inlist and plot you’ve provided.

If the goal is to reproduce the PARSEC results, you’ll want to ensure the
physics and initial conditions in your MESA setup match those in the PARSEC
calculation as closely as possible. Once that alignment is achieved, if
differences still persist, it would be ideal to run both PARSEC and MESA
side by side and compare results throughout the evolutionary stages. This
approach might help identify where the divergence arises.

I hope this helps!

Best,
Matteo

--
Matteo Cantiello - https://www.stellarphysics.org/
Research Scientist,  CCA, Flatiron Institute
Visiting Associate Researcher, Princeton University


On Thu, Jan 23, 2025 at 2:53 PM Torres, Guillermo via Mesa-users <
mesa-users at lists.mesastar.org> wrote:

> All,
>
> I am using MESA r22.11.1 to model the evolution of a rapidly rotating star
> of 5.04 solar masses (initial w/w_crit = 0.55), and I'm finding an odd
> shape for the evolutionary track in the blue hook region, as the star is
> contracting. During this phase, I see the model reaching very high values
> of w/w_crit up to the limit of 0.99, and as it approaches that value, the
> morphology goes haywire, at least compared to a similar track from the
> PARSEC v2.0 series (see figure attached, with the odd part highlighted in
> red). I'm wondering if this really is an issue with the physics in MESA, or
> just that I don't have the right controls in my inlist. It appears the star
> would need to get rid of more of its angular momentum to avoid this, but
> evidently it is not doing that with the controls I am using. I attach my
> inlist for reference. The pre-main-sequence part is computed separately. I
> would be thankful for any suggestions.
>
> Willie
> _______________________________________________
> mesa-users at lists.mesastar.org
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>
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