[Mesa-users] Rotation in massive stars

[Simon Murphy]

Hi Silvana,

Rotation will slow down because the star's radius increases as it evolves on the main sequence. The star also gets a denser core as the mean molecular weight there increases. Conversation of angular momentum therefore suggests the surface should spin down but the core should spin up, unless you are using some physics to redistribute angular momentum throughout the star.

Forgive me for asking, but why do you not want to evolve the star in this way, and to keep the rotation rate fixed, instead?

If you are aiming to have v=300km/s at the TAMS, you might have to start your star rotating faster so that it has slowed to 300km/s at the TAMS.

- Simon
________________________________
From: Mesa-users <mesa-users-bounces at lists.mesastar.org> on behalf of Silvana Vacchina via Mesa-users <mesa-users at lists.mesastar.org>
Sent: 11 March 2022 02:00
To: mesa-users <mesa-users at lists.mesastar.org>
Subject: [Mesa-users] Rotation in massive stars

Dear MESA users,

I'm working on a project for a master degree and I would like to include rotation into my massive stars models, but I've realized that rotation slow down till one factor or less near the end of main sequence (MS) and never rises up again.  Rotation parameters are a bit complicated to me, and I'm not sure if I'm using them properly.

I'm using r15140 and I've run several combinations of parameters without success, with a goal to keep a rotation v at around 300 km/s till He core burning, if that's possible.

Could someone give me some tips on this? Am I missing a parameter maybe? Any help is appreciated.

Thanks in advance,
Silvana
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20220310/37d7fde3/attachment.htm>