Asteroseismology of Red Clump Stars as a Probe of the Dark Matter Content of the Galaxy Central Region

Abstract

Abstract The study of dark matter (DM) captured inside stars has proved to be a viable indirect search strategy complementary to other direct searches. However, in this context, only a fraction of the rich diversity of physics found in different types of stars has been explored, with most studies addressing main-sequence stars and, particularly, the Sun. In this work we focus instead on red clump stars, i.e., core helium-burning stars located in the red end of the horizontal branch. These stars, in some cases with L ≃ 102 L ⊙, can be observed throughout the galaxy and thus can give us insight into the DM conditions found in situ. We consider thermally produced DM particles in the mass range 4–10 GeV with spin-independent annihilation and scattering cross-sections that are close to the observational upper limits from direct detection experiments. Our results show that the evacuation of energy via DM interactions with baryons can cease convection in the central region of the star, which will have a measurable impact on the asteroseismology of the star. This result is particularly interesting for densities that are appropriate for stars within the central few parsecs of the Milky Way. We also explore the prospect of using these effects to study the content of DM in the Milky Way core.