Asteroseismology of red giants

• Project Description: The detection of gravity-mode period spacing in red giants represents one of the groundbreaking results of the asteroseismology programme of both Kepler and COROT (Bedding et al. 2011 Nature 471, 608, Mosser et al. 2011 A&A 532, A86). The interpretation of such period spacing, however, is still in its infancy. The aim of this project is to investigate how the internal structure of giants determines the asymptotic period spacing of high-order gravity modes (ΔP). Students will use the MESA code to compute stellar models along the red-giant branch and in the core-helium burning phase. By using simple asymptotic expressions they will investigate how ΔP depends on stellar mass and evolutionary state, and relate their findings to properties of the internal structure of such stars.

• Recommended Reading: Students should be familiar with the basic properties of oscillation modes (see e.g. Chapter 1, and in particular Sec. 1.4 of 'Asteroseismology', Aerts, Christensen-Dalsgaard, and Kurtz, Springer). More detailed information on the detection and interpretation of period spacing in giants can be found in Bedding et al. 2011 Nature 471, 608, and Bildsten et al. 2012 Ap J 744

• Software: Students will be briefly introduced to the MESA stellar structure and evolution code http://mesa.sourceforge.net/. Knowledge of a scripting and plotting tool will also be useful.