[Mesa-users] YNT: Minimum requirement for blue loops for supergiants
Warrick Ball
W.H.Ball at bham.ac.uk
Thu Apr 11 02:39:50 EDT 2019
Hi G\F6khan,
You only need to recompile (i.e. run `./clean` and `./mk`) if you have
modified source code files. e.g. `src/run_star_extras.f`. The inlists are
read when you run MESA, so if all you've done is modify an inlist, you
don't need to recompile.
Also, it's better to open a new thread for a new topic.
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 Thu, 11 Apr 2019, gokhanyucel at akdeniz.edu.tr wrote:
> Hi,
>
> It might be a "rookie" suggestion but do you user "./clean" and "./mk" commands before start a new evolution?
> It happened to me before. When I tried to change of initial_mass in the file but the end was still same so I figured out I have to use "./clean" and "./mk" command before start a new session.
>
> Cheers,
> G\F6khan
> ________________________________________
> Kimden: Warrick Ball via Mesa-users [mesa-users at lists.mesastar.org] ad\FDna Mesa-users [mesa-users-bounces at lists.mesastar.org]
> G\F6nderildi: 11 Nisan 2019 Per\FEembe 09:16
> Kime: Jeremy Sakstein
> Bilgi: mesa-users
> Konu: Re: [Mesa-users] Minimum requirement for blue loops for supergiants
>
> Hi Jeremy,
>
>> I do indeed have some extra code but the extra control parameter being
>> zero essentially switches it off.
>
> Like Koushik, I also didn't have a problem running your inlist, so it
> sounds like your extra code is influencing MESA's results even when it's
> "essentially switched off".
>
> 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 Wed, 10 Apr 2019, Jeremy Sakstein wrote:
>
>> Hi everyone,
>>
>> One final question if you don\92t mind. I\92m trying to go to higher masses and the loops seem to be hit or miss. Does anyone have any intuition for how I should vary the over shooting, semi convection, and
>> mixing length parameters as I go up in mass?
>>
>> Cheers,
>>
>> Jeremy
>>
>> On Wed, Apr 10, 2019 at 2:16 PM Jeremy Sakstein <sakstein at sas.upenn.edu> wrote:
>> Hi Aaron,
>> I do indeed have some extra code but the extra control parameter being zero essentially switches it off.
>>
>> Cheers,
>>
>> Jeremy
>>
>>
>>
>> On Wed, Apr 10, 2019 at 2:14 PM Aaron Dotter <aaron.dotter at gmail.com> wrote:
>> Hi Jeremy,
>> In addition to Koushik's very helpful response, I noticed that you have
>>
>> use_other_cgrav=.true.
>>
>> in your inlist. If you have some other code that we can't see, it may be partially responsible for the problems you're encountering.
>>
>> Cheers,
>> Aaron
>>
>> On Wed, Apr 10, 2019 at 12:33 PM Koushik Sen via Mesa-users <mesa-users at lists.mesastar.org> wrote:
>> Hi Jeremy,
>>
>> I ran your inlist in Mesa r10108. I have attached my plot with the mail.
>>
>> 1) You need to set Zbase equal to initial_z in the inlist since you are using Type2opacities.
>>
>> 2) I ran two models: one with alpha_mlt = 1.73 and the other 1.3. The models are till the end of He-burning. I do see a blue loop for 1.3 and a blue hook for 1.73.
>>
>> It seems to stop due to too many backups high up the Hyashi track.
>>
>>
>> I did not get any problems like this though, the code ran smoothly.
>>
>> Cheers,
>> Koushik
>>
>>
>>
>> On Wed, Apr 10, 2019 at 10:40 AM Koushik Sen <senkoushik1995 at gmail.com> wrote:
>> Hi Jeremy,
>>
>> I am not an expert on Cepheid variable stars or the instability strip. However, as far as I know, in the stellar models, it is mainly the mixing length parameter that
>> controls the temperature of the Hayashi line (Kippenhahn & Weigert 1990).
>> I could not understand what you meant by very long simulations. You should get blue loops in the core He-burning phase of the stars. So, your stopping condition should be at
>> least till the end of He burning. You can also share the inlists you are using so that we can reproduce your models ourselves.
>>
>> Cheers,
>> Koushik
>>
>> On Wed, 10 Apr 2019 at 16:22, Jeremy Sakstein <sakstein at sas.upenn.edu> wrote:
>> Thanks Koushik!
>> I just tried with alpha_semiconvenction = 10 and so far I am not seeing any loops. The Hyashi track also seems to be inside the instability strip? One thing I noticed is
>> that the time-step is very small. Do I need very long simulations to see these loops?
>>
>> Cheers,
>>
>> Jeremy
>>
>> On Wed, Apr 10, 2019 at 4:31 AM Koushik Sen <senkoushik1995 at gmail.com> wrote:
>> Hi Jeremy,
>>
>> You need efficient semi-convection (alpha_semiconvection=1 or higher, preferably 10) to get blue loops in this mass range. More efficient semiconvection
>> implies more mixing above the He-core, the hydrogen gradient gets steeper and steeper H gradients favour more BSGs. The overshooting parameter that you are
>> using is fine. The lesser overshooting you use, the smaller will be the He core formed, and you'll be more likely to get BSG solutions, but even
>> step_overshoot_f_above_burn_h_core=0.11 should be good enough if you use alpha_semiconvection = 10. For more details on how overshooting and semi-convection
>> affects the evolution of massive stars, you can have a look at this paper: http://adsabs.harvard.edu/abs/2019arXiv190310423S.
>>
>> Hope this helps,
>>
>> Cheers,
>> Koushik
>>
>> On Tue, 9 Apr 2019 at 21:14, Jeremy Sakstein <sakstein at sas.upenn.edu> wrote:
>> Hi Everyone,
>> I've been trying to get blue loops for supergiant stars (13M and higher) by starting from a preMS model and evolving. My inlist works perfectly for lower mass
>> stars but I don't see the loops for higher masses.
>>
>> I know that these loops are very sensitive to things like overshooting so I was wondering if anyone had an idea of what the minimum controls I need are to see
>> these loops?
>>
>> I am using the default X and Y with initial Z=0.0006. At the moment, I am just turning the Ledoux criterion on and setting alpha_semiconvection=0.1. I tried
>> several different mixing lengths and overshoot fractions (in the range 0.01 to 0.1) but so far I see nothing.
>>
>> I'd be very grateful for any help you can give.
>>
>> Cheers,
>>
>> Jeremy
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