Richard Townsend, UW-Madison
MESA & GYRE: Stellar Astrophysics for the People
Physics – Room 481

MESA (Modules for Experiments in Stellar Astrophysics) is a numerical code for modeling the structure and evolution of all types of stellar objects, from brown dwarfs through to the most massive stars in the Universe. It is available to everyone under an open source license, and since its release in 2011 has drawn an impressive following in the stellar astrophysics community. GYRE (acronym pending) is a complementary open source code for calculating the oscillation frequencies of models produced by MESA and other stellar evolution codes. By comparing these eigenfrequencies against the oscillation spectrum of a real star (observed, e.g., by the Kepler satellite) one can place constraints on the structure of the star — the technique of ‘asteroseismology’. In the past year, GYRE has been integrated into MESA so that this process can be largely automated.

In this presentation I’ll give an overview of the physics, numerics and capabilities of MESA and GYRE. I’ll discuss the communities of practice that have sprung up around these codes, and describe how these communities are being further nurtured. I’ll then present some of the exciting projects enabled by the codes, including topics such as observational signatures of core helium flashes; stellar probes of dark-matter physics; pre-supernova winds due to neutrino losses; angular momentum transport by internal gravity waves; surface nuclear burning on accreting neutron stars; and the evolution of white-dwarf merger products.