Evolutionary states of red-giant stars from grid-based modelling

Abstract

From its surface properties it can be difficult to determine whether a red-giant star is in its helium-core-burning phase or only burning hydrogen in a shell around an inert helium core. Stars in either of these stages can have similar effective temperatures, radii and hence luminosities, i.e. they can be located at the same position in the Hertzsprung-Russell diagram. Asteroseismology -- the study of the internal structure of stars through their global oscillations -- can provide the necessary additional constraints to determine the evolutionary states of red-giant stars. Here, we present a method that uses grid-based modelling based on global asteroseismic properties (${\nu }_{\max }$, frequency of maximum oscillation power; and $\Delta \nu$, frequency spacing between modes of the same degree and consecutive radial orders) as well as effective temperature and metallicity to determine the evolutionary phases. This method is applicable even to timeseries data of limited length, although with a small fraction of miss-classifications.

arXiv commentTo appear in the Proceedings of the joint TASC2/KASC9 workshop - SPACEINN & HELAS8 conference: 4 pages, 1 figure

References in corpus (10)

• The Transiting Exoplanet Survey Satellite
• A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones
• Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars
• The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields
• Mixed modes in red giants: a window on stellar evolution
• A critical investigation on the discrepancy between the observational and theoretical Red Giant luminosity function "Bump"
• Evolutionary influences on the structure of red-giant acoustic oscillation spectra from 600d of Kepler observations
• A new analysis of the Red Giant Branch "Tip" distance scale and the value of the Hubble constant
• Significantly improving stellar mass and radius estimates: A new reference function for the Δν scaling relation
• Asteroseismic surface gravity for evolved stars

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• KIC 2568888: To be or not to be a binary