Stellar convective cores as dark matter probes

TL;DR

This paper uses the detection of a convective core in a star to test dark matter models, showing that certain dark matter scenarios are incompatible with stellar observations.

Contribution

It demonstrates how stellar asteroseismology can constrain dark matter properties, providing a novel astrophysical test for dark matter models.

Findings

Asymmetric dark matter models are incompatible with the observed convective core in KIC 2009505.

Stellar oscillation data can effectively test dark matter particle properties.

The presence of a convective core constrains dark matter models in the 1.1-1.3 solar mass range.

Abstract

The recent detection of a convective core in a main-sequence solar-type star is used here to test particular models of dark matter (DM) particles, those with masses and scattering cross sections in the range of interest for the DM interpretation of the positive results in several DM direct detection experiments. If DM particles do not effectively self-annihilate after accumulating inside low-mass stars (e.g. in the asymmetric DM scenario) their conduction provides an efficient mechanism of energy transport in the stellar core. For main-sequence stars with masses between 1.1 and 1.3 Msun, this mechanism may lead to the suppression of the inner convective region expected to be present in standard stellar evolution theory. The asteroseismic analysis of the acoustic oscillations of a star can prove the presence/absence of such a convective core, as it was demonstrated for the first time with the Kepler field main-sequence solar-like pulsator, KIC 2009505. Studying this star we found that the asymmetric DM interpretation of the results in the CoGeNT experiment is incompatible with the confirmed presence of a small convective core in KIC 2009505.