Constraining the near-core rotation of the gamma Doradus star 43 Cygni using BRITE-Constellation data

Abstract

Photometric time series of the $\gamma$ Dor star 43 Cyg obtained with the BRITE-Constellation nano-satellites allow us to study its pulsational properties in detail and to constrain its interior structure. We aim to find a g-mode period spacing pattern that allows us to determine the near-core rotation rate of 43 Cyg and redetermine the star's fundamental atmospheric parameters and chemical composition. We conducted a frequency analysis using the 156-days long data set obtained with the BRITE-Toronto satellite and employed a suite of MESA/GYRE models to derive the mode identification, asymptotic period spacing and near-core rotation rate. We also used high-resolution, high signal-to-noise ratio spectroscopic data obtained at the 1.2m Mercator telescope with the HERMES spectrograph to redetermine the fundamental atmospheric parameters and chemical composition of 43 Cyg using the software Spectroscopy Made Easy (SME). We detected 43 intrinsic pulsation frequencies and identified 18 of them to be part of a period spacing pattern consisting of prograde dipole modes with an asymptotic period spacing $\Delta {\Pi }_{l=1}$ of $2970_{-570}^{+700}\mathrm{s}$. The near-core rotation rate was determined to be $f_{\mathrm{rot}}=0.56_{-0.14}^{+0.12}{\mathrm{d}}^{-1}$. The atmosphere of 43 Cyg shows solar chemical composition at an effective temperature of 7150 $\pm$ 150 K, a log g of 4.2 $\pm$ 0.6 dex and a projected rotational velocity, $v\sin i$, of 44 $\pm$ 4 kms${}^{-1}$. The morphology of the observed period spacing patterns shows indications of the presence of a significant chemical gradient in the stellar interior.

arXiv comment9 pages, 8 figures, accepted by A&A

References in corpus (37)

• 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
• Kepler Mission Design, Realized Photometric Performance, and Early Science
• 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
• Spectroscopy Made Easy: Evolution
• Seismic diagnostics for transport of angular momentum in stars 1. Rotational splittings from the PMS to the RGB
• Angular momentum transport within evolved low-mass stars
• Internal Gravity Waves in Massive Stars: Angular Momentum Transport
• Probing the properties of convective cores through g modes: high-order g modes in SPB and gamma Doradus stars
• Gamma Doradus Stars: Defining a New Class of Pulsating Variables
• Asteroseismic measurement of surface-to-core rotation in a main sequence A star, KIC 11145123
• BRITE-Constellation: nanosatellites for precision photometry of bright stars
• The interior rotation of a sample of gamma Doradus stars from ensemble modelling of their gravity mode period spacings
• Tight asteroseismic constraints on core overshooting and diffusive mixing in the slowly rotating pulsating B8.3V star KIC 10526294
• Asteroseismic measurement of slow, nearly-uniform surface-to-core rotation in the main sequence F star KIC 9244992
• Sub-Inertial Gravity Modes in the B8V Star KIC 7760680 Reveal Moderate Core Overshooting and Low Vertical Diffusive Mixing
• The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets
• A new asteroseismic diagnostic for internal rotation in $\gamma$ Doradus stars
• A detection threshold in the amplitude spectra calculated from Kepler data obtained during K2 mission
• Asteroseismic modelling of the two F-type hybrid pulsators KIC10080943A and KIC10080943B
• The internal rotation profile of the B-type star KIC10526294 from frequency inversion of its dipole gravity modes and statistical model comparison
• On the Differential Rotation of Massive Main Sequence Stars
• Detecting non-uniform period spacings in the Kepler photometry of gamma Doradus stars: methodology and case studies
• The BRITE Constellation nanosatellite mission: Testing, commissioning and operations
• KIC 10080943: a binary star with two $\gamma$ Doradus/$\delta$ Scuti hybrid pulsators. Analysis of the g modes
• Spectrum Analysis of Bright Kepler Gamma Doradus Candidate Stars
• Accuracy of atmospheric parameters of FGK dwarfs determined by spectrum fitting
• Massive pulsating stars observed by BRITE-Constellation. I. The triple system Beta Centauri (Agena)
• BRITE-Constellation: Data processing and photometry
• Mode density and frequency extraction in the delta Scuti star HD 50844
• Strong interactions between g- and p-modes in the hybrid gamma Doradus-delta Scuti CoRoT star ID105733033
• Echelle diagrams and period spacings of g modes in gamma Doradus stars from four years of Kepler observations
• Search for exoplanets around pulsating stars of A--F type in Kepler Short Cadence data and the case of KIC 8197761
• Period spacing of gravity modes strongly affected by rotation. Going beyond the traditional approximation

Cited by in corpus (11)

• On the sensitivity of gravito-inertial modes to differential rotation in intermediate-mass main-sequence stars
• Rotation of the convective core in $\gamma$ Dor stars measured by dips in period spacings of g modes coupled with inertial modes
• Multiplicity of Galactic Cepheids and RR Lyrae stars from Gaia DR2 -- II. Resolved common proper motion pairs
• Revisiting the pulsational characteristics of the exoplanet host star $\beta$ Pictoris
• Astrophysical properties of 15062 Gaia DR3 gravity-mode pulsators: pulsation amplitudes, rotation, and spectral line broadening
• Tango of celestial dancers: A sample of detached eclipsing binary systems containing g-mode pulsating components. A case study of KIC9850387
• Pulsational instability of pre-main sequence models from accreting protostars. I. Constraining the input physics for accretion with spectroscopic parameters and stellar pulsations
• beta Cas: the first delta Scuti star with a dynamo magnetic field
• Backtracing the internal rotation history of the $\beta$ Cep star HD 129929
• Space Photometry with BRITE-Constellation
• The near-core rotation of HD 112429: a gamma Doradus star with TESS photometry and legacy spectroscopy