Helium burning in moderate-mass stars

TL;DR

This paper reviews the evolution of low- and intermediate-mass stars during core helium burning, emphasizing structural differences and seismic diagnostics to identify stellar phases despite overlapping regions in the Hertzsprung-Russell diagram.

Contribution

It highlights the potential of seismic diagnostics to distinguish stellar evolutionary phases based on internal structural differences.

Findings

Structural differences can identify stellar phases.

Seismic diagnostics sensitive to core conditions are promising.

Potential to differentiate stars despite similar HR diagram positions.

Abstract

The evolution of low- and intermediate mass stars at the onset and during core helium burning is reviewed. Particular emphasis is laid on structural differences, which may allow to identify a star's nature and evolutionary phase in spite of the fact that it is found in a region of the Hertzsprung-Russell-Diagram objects from both mass ranges may populate. Seismic diagnostics which are sensitive to the temperature and density profile at the border of the helium core and outside of it may be the most promising tool.