Asteroseismology of hybrid δ Scuti-γ Doradus pulsating stars

SANCHEZ ARIAS, J.; CÓRSICO, A. H.; ALTHAUS, L. G.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2017 vol. 597

0004-6361

Context. Hybrid δ Scuti-γ Doradus pulsating stars showacoustic (p) oscillation modes typical of δ Scuti variable stars,and gravity (g) pulsation modes characteristic of γ Doradusvariable stars simultaneously excited. Observations from space missionssuch as MOST, CoRoT, and Kepler have revealed a large number of hybridδ Scuti-γ Doradus pulsators, thus paving the way for anexciting new channel of asteroseismic studies. Aims: We performdetailed asteroseismological modelling of five hybrid δScuti-γ Doradus stars. Methods: A grid-based modelingapproach was employed to sound the internal structure of the targetstars using stellar models ranging from the zero-age main sequence tothe terminal-age main sequence, varying parameters such as stellar mass,effective temperature, metallicity and core overshooting. Theiradiabatic radial (ℓ = 0) and non-radial (ℓ = 1,2,3) p and g modeperiods were computed. Two model-fitting procedures were used to searchfor asteroseismological models that best reproduce the observedpulsation spectra of each target star. Results: We derive thefundamental parameters and the evolutionary status of five hybridδ Scuti-γ Doradus variable stars recently observed by theCoRoT and Kepler space missions: CoRoT 105733033, CoRoT 100866999, KIC11145123, KIC 9244992, and HD 49434. The asteroseismological model foreach star results from different criteria of model selection, in whichwe take full advantage of the richness of periods that characterises thepulsation spectra for this kind of star.