An in-depth study of HD 174966 with CoRoT photometry and HARPS spectroscopy. Large separation as a new observable for δSct stars

Abstract

The aim of this work was to use a multi-approach technique to derive the most accurate values possible of the physical parameters of the δSct star HD174966. In addition, we searched for a periodic pattern in the frequency spectra with the goal of using it to determine the mean density of the star. First, we extracted the frequency content from the CoRoT light curve. Then, we derived the physical parameters of HD174966 and carried a mode identification out from the spectroscopic and photometric observations. We used this information to look for the models fulfilling all the conditions and discussed the inaccuracies of the method because of the rotation effects. In a final step, we searched for patterns in the frequency set using a Fourier transform, discussed its origin and studied the possibility of using the periodicity to obtain information about the physical parameters of the star. A total of 185 peaks were obtained from the Fourier analysis of the CoRoT light curve, being almost all reliable pulsating frequencies. From the spectroscopic observations, 18 oscillation modes were detected and identified, and the inclination angle ($62.5^{\circ }$${}_{-17.5}^{+7.5}$) and the rotational velocity of the star (142 km/s) were estimated. From the multi-colour photometric observations, 3 frequencies were detected, which correspond to the main ones in the CoRoT light curve. We looked for periodicities within the 185 frequencies and found a periodic pattern ~64 μHz. Using the inclination angle, the rotational velocity and an Echelle diagram, showing a double comb outside the asymptotic regime, we concluded that the periodicity corresponds to a large separation structure. The periodic pattern allowed us to discriminate models from a grid, finding that the value of the mean density is achieved with a 6% uncertainty. So, the pattern could be used as a new observable for A-F type stars.

15 pages, 10 figures, 6 tables

References in corpus (11)

• CESAM: a free code for stellar evolution calculations
• Acoustic oscillations of rapidly rotating polytropic stars. II. Effects of the Coriolis and centrifugal accelerations
• A heuristic derivation of the uncertainty of the frequency determination in time series data
• Acoustic oscillations in rapidly rotating polytropic stars I. Effects of the centrifugal distortion
• A new method for the spectroscopic identification of stellar non-radial pulsation modes. I. The method and numerical tests
• Regular patterns in the acoustic spectrum of rapidly rotating stars
• Mode visibilities in rapidly rotating stars
• Pulsation spectrum of Delta Sct stars: the binary HD 50870 as seen with CoRoT and HARPS
• Granada oscillation Code (GraCo)
• FILOU oscillation code
• A comprehensive asteroseismic modelling of the high-amplitude delta Scuti star RV Arietis

Cited by in corpus (33)

• The PLATO 2.0 Mission
• Characterising the observational properties of δ Sct stars in the era of space photometry from the Kepler mission
• Very regular high-frequency pulsation modes in young intermediate-mass stars
• On the photometric detection of Internal Gravity Waves in upper main-sequence stars I. Methodology and application to CoRoT targets
• Observational $\Delta \nu$-$\bar{\rho }$ relation for $\delta$ Sct stars using eclipsing binaries and space photometry
• Measuring mean densities of delta Scuti stars with asteroseismology. Theoretical properties of large separations using TOUCAN
• Kepler Eclipsing Binaries with $\delta$ Scuti/$\gamma$ Doradus Pulsating Components 1: KIC 9851944
• Precise surface gravities of $\delta$ Scuti stars from asteroseismology
• Unexpected series of regular frequency spacing of delta Scuti stars in the non-asymptotic regime -- II. Sample -- echelle diagrams and rotation
• Frequency regularities of acoustic modes and multi-colour mode identification in rapidly rotating stars
• Unexpected series of regular frequency spacing of delta Scuti stars in the non-asymptotic regime -- I. The methodology
• Oscillations of 2D ESTER models. I. The adiabatic case
• Convection and Overshoot in models of gamma Doradus and delta Scuti stars
• Semi-empirical seismic relations of A-F stars from CoRoT and Kepler legacy data
• Dating young open clusters using delta Scuti stars. Results for Trumpler 10 and Praesepe
• Study of the low-order $\Delta \nu$-$\bar{\rho }$ relation for moderately-rotating $\delta$ Scuti stars and its impact on their characterisation
• Study of rotational splittings in $\delta$~Scuti stars using pattern finding techniques
• Asteroseismology of the $\delta$ Scuti star HD 50844
• Impact of gaps in the asteroseismic characterization of pulsating stars. I. On the efficiency of pre-whitening
• Exploring the helium core of the delta Scuti star CoRoT 102749568 with asteroseismology
• Rotational splitting and asteroseismic modelling of the delta Scuti star EE Camelopardalis
• HD 51844: An Am delta Scuti in a binary showing periastron brightening
• Self-consistent method to extract non-linearities from pulsating stars light curves I. Combination frequencies
• Regularities in the spectrum of chaotic p-modes in rapidly rotating stars
• The Delta Scuti star 38 Eri from the ground and from space
• Non-adiabatic pulsations in ESTER models
• Modelling $\delta$ Scuti pulsations: A new grid of p, g, and f modes across pre-main-sequence to post-main-sequence evolution
• EPIC 202843107 : A Close Eclipsing Binary Containing a δ Scuti Variable
• Internal rapid rotation and its implications for stellar structure and pulsations
• Chronos --- Taking the pulse of our Galactic neighbourhood (ESA Voyage 2050 White Paper)
• Scaling of oscillation frequencies in rotating stars
• Asteroseismology of 35 Kepler and TESS $\delta$ Scuti stars near the red edge of the instability strip. The limitations of $\delta$ Scuti stars for dating open clusters
• KIC 3868420: A high-amplitude $\delta$ Scuti-$\gamma$ Dor hybrid star crossing the Hertzsprung gap