[mesa-users] "failed to find all required l=0 modes"

[Warrick Ball]

Hi,

I was looking at the results of a recent asteroseismic fitting run using 
ersion 7184, and found errors of the form

"failed to find all required l=0 modes"

after nearly every chi^2 evaluation in the range where only the radial 
modes are considered.  This came as a surprise, since the code was 
returning a useful value of  chi^2.

I grepped the error message and identified it's source at line 375 of 
star/astero/src/extras_support.f.  The message is displayed when the 
function get_radial returns a false.  I then had a look at get_radial 
(line 631).

     if (chi2_radial > chi2_radial_limit .and. nl1 + nl2 + nl3 > 0) then
        write(*,'(a50,i6,99f16.2)') &
           'chi2_radial > chi2_radial_limit', &
               s% model_number, chi2_radial, chi2_radial_limit
        return
     end if
     get_radial = .true.

I might be misinterpreting the code, but it looks to me like this will 
leave get_radial as false if chi2_radial > chi2_radial_limit, and thus the 
error will be printed.  But the error message doesn't correspond to what's 
actually happened.  That is, the modes have all been found, but the 
current value of chi^2 is too large for it to be worth continuing to 
evaluate the higher-degree modes.

If I'm right, then the fix is simply to put get_radial = .true. before the 
last if block.  But, as always, I might be wrong...

Cheers,
Warrick



------------
Warrick Ball
Postdoc, Institut für Astrophysik Göttingen
wball at astro.physik.uni-goettingen.de
+49 (0) 551 39 5069