The GYRE Forums

Hi all,

I was taking a deeper look at the displacements xi_r and xi_h of the eigenfunctions. The documentation states that these are given in units of R_star. But they take values bigger than one. How can this be? Displacements are larger than the stellar radius? Or am I misunderstanding something here?

Greetings
Jess

KrawalloQualle wrote: ↑

Sun May 19, 2019 10:23 am

Hi all,

I was taking a deeper look at the displacements xi_r and xi_h of the eigenfunctions. The documentation states that these are given in units of R_star. But they take values bigger than one. How can this be? Displacements are larger than the stellar radius? Or am I misunderstanding something here?

Greetings
Jess

Since GYRE is a linear oscillation code, their normalization is arbitrary. The default normalization convention is that the total mode energy (in units of GM^2/R) is unity, and that may lead to surface values of xi_r and xi_h that exceed R_star. Of course, when using the eigenfunctions to model observations, they can be re-scaled to match the (much smaller) observed surface displacements and/or velocities.

cheers,

Rich

Ah, of course. I should have thought about that. Sorry for the dumb question and thank you very much for the fast answer.

Cheers
Jess