Asteroseismology of Red Giant stars

TL;DR

This paper discusses the analysis of Sun-like oscillations in Red Giant stars, focusing on detection challenges and methods for extracting asteroseismic parameters from long-term observational data.

Contribution

It introduces a robust peak-bagging analysis procedure for identifying oscillation modes in Red Giants using multi-year SMEI data.

Findings

Successful identification of oscillation modes in multiple Red Giants

Development of techniques to distinguish true signals from noise

Insights into the asteroseismic properties of evolved stars

Abstract

Sun-like oscillations, that is p-modes excited stochastically by convective noise, have now been observed in a number of Red Giant stars. Compared to those seen in the Sun, these modes are of large amplitude and long period, making the oscillations attractive prospects for observation. However, the low Q-factor of these modes, and issues relating to the rising background at low frequencies, present some interesting challenges for identifying modes and determining the related asteroseismic parameters. We report on the analysis procedure adopted for peak-bagging by our group at Birmingham, and the techniques used to robustly ensure these are not a product of noise. I also show results from a number of giants extracted from multi-year observations with the SMEI instrument.