[Mesa-users] Creating a Highly Irradiated Super-Earth

[Brian Jackson]

It's actually reassuring. At least I wasn't goofing something up. I'll
figure out some science workaround.

Thanks very much for the quick response,
Brian

On Fri, Jan 24, 2020 at 2:37 PM Bill Paxton <paxton at kitp.ucsb.edu> wrote:
>
> this is definitely running into EOS problems.  (negative gamma1 -> imaginary sound speed)
>
> it may well be related to a blending glitch combining OPAL eos and PC eos.
>
> the solution is not likely to be trivial, so don’t hold your breath.
>
> we’ll work on it, but it may take some significant time to fix.
>
> sorry for the disappointing news.
>
> b
>
>
>
>
>
> > On Jan 24, 2020, at 11:53 AM, Brian Jackson <bjackson at boisestate.edu> wrote:
> >
> > I've conducted additional experiments, and I think I'm starting to see
> > what the issues might be.
> >
> > I've attached inlists and a model for a slightly different approach.
> > The model calculation behaves fine until about 4 Gyrs out, when the
> > timestep suddenly plunges and the code fails to complete the run. For
> > some reason, the central degeneracy parameter goes haywire shortly
> > before the run ends -- see attached History_Plot.png.
> >
> > Looking at the 2011 MESA instrument
> > (https://ui.adsabs.harvard.edu/abs/2011ApJS..192....3P/abstract), it
> > seems the model core may be nearing a transition in the equation of
> > state (log(density) = -0.19, log(temp) = 3.79 -- see attached Figure
> > 1). Is there a reason why that transition would severely and abruptly
> > modify the degeneracy parameter? Is there a way to smooth this
> > evolutionary phase?
> >
> > Or have I completely misunderstood what's going on?
> >
> > Thanks,
> > Brian
> >
> > On Wed, Jan 22, 2020 at 5:58 PM Brian Jackson <bjackson at boisestate.edu> wrote:
> >>
> >> Dear MESA Users,
> >> I am still struggling to create highly-irradiated super-Earths using MESA.
> >>
> >> I have attached the inlists and saved models I'm using to create a
> >> 20-Earth mass planet with an envelope mass fraction of 20% (i.e., a
> >> core mass of 16 Earth masses) and an irradiation 20 times Earth's
> >> (i.e., 2.72e7 ergs/s/cm^2).
> >>
> >> I attempt to create the planet by irradiating a gas giant planet and
> >> then relaxing the mass down to my desired mass. (I've found doing it
> >> the other way around leads to badness.) I've tried tweaking lots of
> >> settings, but nothing seems to work. In the end, I wind up with a
> >> timestep below the suggested minimum of 9.9999999999999995D-07.
> >>
> >> I am using Mac OS 10.13.1, MESA 11701, and the most recent version of
> >> the SDK (August 30 2019).
> >>
> >> Please forgive me if I forgot any required information.
> >>
> >> Thanks,
> >> Brian
> > <inlist><inlist_pgstar><history_columns.list><LF14_planet_relaxedM_20_ME_10-percent.mod><Paxton2011_Fig1.png><History_Plot.png>_______________________________________________
> > mesa-users at lists.mesastar.org
> > https://lists.mesastar.org/mailman/listinfo/mesa-users
> >
>