A binary with a ~Scuti star and an oscillating red giant: orbit and asteroseismology of KIC9773821
arXiv:2105.13577 · doi:10.1093/mnras/stab1436
Abstract
We study the Scuti -- red giant binary KIC9773821, the first double-pulsator binary of its kind. It was observed by \textit{Kepler} during its four-year mission. Our aims are to ascertain whether the system is bound, rather than a chance alignment, and to identify the evolutionary state of the red giant via asteroseismology. An extension of these aims is to determine a dynamical mass and an age prior for a Sct star, which may permit mode identification via further asteroseismic modelling. We determine spectroscopic parameters and radial velocities (RVs) for the red giant component using HERMES@Mercator spectroscopy. Light arrival-time delays from the Sct pulsations are used with the red-giant RVs to determine that the system is bound and to infer its orbital parameters, including the binary mass ratio. We use asteroseismology to model the individual frequencies of the red giant to give a mass of M and an age of Gyr. We find that it is a helium-burning secondary clump star, confirm that it follows the standard scaling relation, and confirm its observed period spacings match their theoretical counterparts in the modelling code MESA. Our results also constrain the mass and age of the Sct star. We leverage these constraints to construct Sct models in a reduced parameter space and identify four of its five pulsation modes.
arXiv commentAccepted for publication in MNRAS
References in corpus (69)
- The chemical composition of the Sun
- Modules for Experiments in Stellar Astrophysics (MESA)
- Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
- Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
- Modules for Experiments in Stellar Astrophysics (MESA): Convective Boundaries, Element Diffusion, and Massive Star Explosions
- Stellar Multiplicity
- Low Temperature Opacities
- Mind your Ps and Qs: the Interrelation between Period (P) and Mass-ratio (Q) Distributions of Binary Stars
- Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars
- Asteroseismology of Solar-Type and Red-Giant Stars
- GYRE: An open-source stellar oscillation code based on a new Magnus Multiple Shooting Scheme
- HERMES: a high-resolution fibre-fed spectrograph for the Mercator telescope
- Stellar, Brown Dwarf, and Multiple Star Properties from Hydrodynamical Simulations of Star Cluster Formation
- Testing Scaling Relations for Solar-Like Oscillations from the Main Sequence to Red Giants using Kepler Data
- Asteroseismology of old open clusters with Kepler: direct estimate of the integrated RGB mass loss in NGC6791 and NGC6819
- The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields
- The Second APOKASC Catalog: The Empirical Approach
- The VLA Nascent Disk and Multiplicity Survey of Perseus Protostars (VANDAM). II. Multiplicity of Protostars in the Perseus Molecular Cloud
- Probing the core structure and evolution of red giants using gravity-dominated mixed modes observed with Kepler
- Asteroseismic classification of stellar populations among 13000 red giants observed by Kepler
- A new correction of stellar oscillation frequencies for near-surface effects
- Mixed modes in red giants: a window on stellar evolution
- Stellar population synthesis based modelling of the Milky Way using asteroseismology of 13000 Kepler red giants
- Galactic Archaeology with asteroseismic ages: evidence for delayed gas infall in the formation of the Milky Way disc
- Period spacings in red giants II. Automated measurement
- Efficiency of mass transfer in massive close binaries, Tests from double-lined eclipsing binaries in the SMC
- Giant star seismology
- {\em Gaia}-derived luminosities of {\em Kepler} A/F stars and the pulsator fraction across the δ Scuti instability strip
- FM stars: A Fourier view of pulsating binary stars, a new technique for measuring radial velocities photometrically
- Characterising the observational properties of δ Sct stars in the era of space photometry from the Kepler mission
- Super-Nyquist asteroseismology with the Kepler Space Telescope
- Oscillating K giants with the WIRE satellite: determination of their asteroseismic masses
- Towards stellar effective temperatures and diameters at one per cent accuracy for future surveys
- Very regular high-frequency pulsation modes in young intermediate-mass stars
- Finding binaries from phase modulation of pulsating stars with Kepler: V. Orbital parameters, with eccentricity and mass-ratio distributions of 341 new binaries
- Grid Search in Stellar Parameters: a software for spectrum analysis of single stars and binary systems
- Finding binaries among Kepler pulsating stars from phase modulation of their pulsations
- On using the CMD morphology of M67 to test solar abundances
- Detached double-lined eclipsing binaries as critical tests of stellar evolution : Age and metallicity determinations from the HR diagram
- Investigating the Metallicity-Mixing Length Relation
- Classically and Asteroseismically constrained 1D Stellar Evolution Models of Centauri A and B using Empirical Mixing Length Calibrations
- The GALAH Survey: Chemodynamics of the Solar Neighbourhood
- Models of alpha Centauri A and B with and without seismic constraints: time dependence of the mixing-length parameter
- The treatment of mixing in core helium burning models -- II. Constraints from cluster star counts
- A precise asteroseismic age and metallicity for HD 139614: a pre-main-sequence star with a protoplanetary disc in Upper-Centaurus Lupus
- Interferometric diameters of five evolved intermediate-mass planet-hosting stars measured with PAVO at the CHARA Array
- Kepler red-clump stars in the field and in open clusters: constraints on core mixing
- Denoising spectroscopic data by means of the improved Least-Squares Deconvolution method
- Deriving the orbital properties of pulsators in binary systems through their light arrival time delays
- Exploring the stellar age distribution of the Milky Way Bulge using APOGEE
- Asteroseismology of 36 Kepler subgiants -- II: Determining ages from detailed modelling
- Validation of the Frequency Modulation technique applied to the pulsating delta Sct - gamma Dor eclipsing binary star KIC 8569819
- How accurate are stellar ages based on stellar models? II. The impact of asteroseismology
- Finding binaries from phase modulation of pulsating stars with Kepler. IV. Detection limits and radial velocity verification
- Tidally perturbed pulsations in the pre-main sequence Scuti binary RS Cha
- Testing the intrinsic scatter of the asteroseismic scaling relations with Kepler red giants
- Evidence for compact binary systems around Kepler red giants
- Multi-technique investigation of the binary fraction among A-F type candidate hybrid variable stars discovered by Kepler
- Convective-core overshoot and suppression of oscillations: Constraints from red giants in NGC6811
- Forward modeling the orbits of companions to pulsating stars from their light travel time variations
- A window into Sct stellar interiors: Understanding the eclipsing binary system TT Hor
- Binary star detectability in data from phase modulation of different types of oscillations
- Centauri A as a potential stellar model calibrator: establishing the nature of its core
- Study of the Mass-Ratio Distribution of Spectroscopic Binaries. II. The Boundaries of the Brown-Dwarf Desert as Seen with the APOGEE Spectroscopic Binaries
- Characteristics of solar-like oscillations of secondary red clump stars
- Matching the frequency spectrum of PMS stars by means of standard and rotating models
- Spectroscopic confirmation of the binary nature of the hybrid pulsator KIC 5709664 found with the frequency modulation method
- The Formation of Binaries
- Probing core overshooting using asteroseismology