Identification of pulsational modes in rotating slowly pulsating B-type stars

Abstract

Knowledge of the geometry of pulsational modes is a prerequisite for seismic modelling of stars. In the case of slowly pulsating B-type (SPB) pulsators, the simple zero-rotation approach so far used for mode identification is usually not valid because pulsational frequencies are often of the order of the rotational frequency. Moreover, this approach allows us to determine only the spherical harmonic degree, $\ell$, while the azimuthal order, $m$, is beyond its reach. On the other hand, because of the density of oscillation spectra of SPB stars, knowledge of $m$ is indispensable if one wants to assign the radial order, $n$, to the observed frequency peaks. Including the effects of rotation via the traditional approximation, we perform identification of the mode angular numbers ($\ell ,m$) for 31 SPB stars with available multicolour time series photometry. Simultaneously, constraints on the rotational velocity, $V_{\mathrm{rot}}$, and the inclination angle, $i$, are determined assuming uniform rotation and a constant value of $V_{\mathrm{rot}}\sin i$. Dependence of the results on the adopted model is tested using HD\,21071 as an example. Despite some model uncertainties and limitations of the method, our studies show the correct approach to identifying the low-frequency oscillation modes.

arXiv commentaccepted in MNRAS, 21 pages, 9 figures

References in corpus (34)

• The chemical composition of the Sun
• Validation of the new Hipparcos reduction
• An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
• SB9: The Ninth Catalogue of Spectroscopic Binary Orbits
• Present-day cosmic abundances. A comprehensive study of nearby early B-type stars and implications for stellar and Galactic evolution and interstellar dust models
• A Stellar Rotation Census of B Stars: from ZAMS to TAMS
• Rotational velocities of A-type stars IV. Evolution of rotational velocities
• New Periodic Variables from the Hipparcos Epoch Photometry
• Coude-feed stellar spectral library - atmospheric parameters
• Stellar Rotation in Young Clusters. I. Evolution of Projected Rotational Velocity Distributions
• Kepler observations of variability in B-type stars
• Discovery of magnetic fields in the beta Cephei star xi^1 CMa and in several Slowly Pulsating B stars
• Masses and Luminosities of O and B - type stars and red super giants
• Gravito-inertial and pressure modes detected in the B3 IV CoRoT target HD 43317
• Photometric amplitudes and phases of nonradial oscillation in rotating stars
• B Star Rotational Velocities in h and chi Persei: A Probe of Initial Conditions During the Star-Formation Process
• Constraints on stellar convection from multi-colour photometry of Delta Scuti stars
• A new method for the spectroscopic identification of stellar non-radial pulsation modes. I. The method and numerical tests
• Influence of the Coriolis force on the instability of slowly pulsating B stars
• KIC 10526294: a slowly rotating B star with rotationally split, quasi-equally spaced gravity modes
• New Estimates of the Solar-Neighborhood Massive-Stars Birthrate and the Galactic Supernova Rate
• Spectroscopic determination of the fundamental parameters of 66 B-type stars in the field-of-view of the CoRoT satellite
• Tidally induced radial-velocity variations in close binaries
• New magnetic field measurements of beta Cephei stars and Slowly Pulsating B stars
• CoRoT's view on variable B8/9 stars: spots versus pulsations: Evidence for differential rotation in HD 174648
• The Classificiation of Kepler B star Variables
• The CoRoT B-type binary HD50230: a prototypical hybrid pulsator with g-mode period and p-mode frequency spacings
• Abundances determined using Si II and Si III in B-type stars: evidence for stratification
• On the co-existence of chemically peculiar Bp stars, slowly pulsating B stars and constant B stars in the same part of the H-R diagram
• Constraints on opacities from complex asteroseismology of B-type pulsators: the $\beta$ Cephei star $\theta$ Ophiuchi
• R modes of slowly pulsating B stars
• High-precision CoRoT space photometry and fundamental parameter determination of the B2.5V star HD 48977
• Oscillation modes in the rapidly rotating Slowly Pulsating B-type star $\bmu$ Eridani
• Effect of NLTE model atmospheres on photometric amplitudes and phases of early B-type pulsating stars

Cited by in corpus (7)

• Angular momentum transport by heat-driven g-modes in slowly pulsating B stars
• The Magnetic Early B-type Stars I: Magnetometry and Rotation
• Domains of pulsational instability of low-frequency modes in rotating upper main-sequence stars
• Magnetic OB[A] Stars with TESS: probing their Evolutionary and Rotational properties (MOBSTER) - I. First-light observations of known magnetic B and A stars
• Internal rotation and inclinations of slowly pulsating B stars: Evidence of interior angular momentum transport
• Seismic modelling of the rotating, slowly pulsating B-type star HD 21071
• Weak Metallic Emission Lines in Early B-Type Stars