[mesa-users] negative delta nu!?!

[Warrick Ball]

Hi Jean,

On the first issue, I started your run a few minutes ago but it looks 
like it'll take a while to finish.  Out of curiosity, which revision are 
you using?  Your GYRE input gave me a read failure in r9575 (no namelist 
object "diff_scheme") so I've just used the default for now.

Regarding the "failed to find required l=0 modes", I looked into this over 
two years ago:

https://sourceforge.net/p/mesa/mailman/message/33028229/

Ignore my proposed fix: that wasn't the solution.  It seems Rich started 
looking into where the code changed but I couldn't find anything further 
on the mailing lists.  I've cc'ed Rich, in case he can recall if he made 
any progress.

As far as I know, it's nothing to worry about.  But now that you've 
brought it up again, it's inspired me to have another close look at why 
the message is issued and what should be happening instead.  Hopefully 
more as the day progresses here.

Cheers,
Warrick

PS:  I noticed your inlist has the line

       l0_n_obs(:) = 6 ! the observed radial orders (ignored if < 0)

AFAIK, this should be the observed radial orders of the radial modes, 
which presumably aren't all 6!  (You can choose to let MESA infer the 
radial orders of the modes: see lines 660--686 in 
$MESA_DIR/star/astero/work/astero_support.f.)



------------
Warrick Ball
Postdoc, School of Physics and Astronomy
University of Birmingham, Edgbaston, Birmingham B15 2TT
wball at bison.ph.bham.ac.uk
+44 (0)121 414 4552

On Tue, 9 May 2017, Jean McKeever wrote:

> Here are the inlists I used.
> 
> 2017-05-08 17:22 GMT-06:00 Jean McKeever <jeanm12 at nmsu.edu>:
>       Hello,
> 
> I am running some models using astero and have ran into an interesting conundrum. As soon as astero starts computing individual frequencies, the delta_nu value, both printed on the graph display and
> written to the history file, becomes negative.\A0 I am using gyre to compute only radial modes. Has anyone else encountered this or something similar?
> 
> On another note I am constantly getting\A0 a "failed to find required l=0 modes" message, however modes appear on the echelle diagram. I have double checked my gyre input files are in the right units and
> cover the range of observed modes. Is this something to worry about?
> 
> 
> Jean McKeever
> 
> 
> 
>