Short-term variability and mass loss in Be stars IV. Two groups of closely spaced, approximately equidistant frequencies in three decades of space photometry of $\nu$ Puppis (B7-8 IIIe)

Abstract

In early-type Be stars, groups of nonradial pulsation (NRP) modes with numerically related frequencies may be instrumental for the release of excess angular momentum through mass-ejection events. Difference and sum/harmonic frequencies often form additional groups. The goal of this study is to find out whether a similar frequency pattern occurs in the cooler third-magnitude B7-8\,IIIe shell star $\nu$ Pup. Time-series analyses are performed of space photometry with BRITE-Constellation (2015, 2016/17, and 2017/18), SMEI (2003--011), and Hipparcos (1989-1993). Two IUE SWP and 27 optical echelle spectra spanning 20 years were retrieved from various archives. The optical spectra exhibit no anomalies or well-defined variabilities. A magnetic field was not detected. All three photometry satellites recorded variability near 0.656 c/d which is resolved into three features separated by ~0.0021 c/d. First harmonics form a second frequency group, also spaced by ~0.0021 c/d. The frequency spacing is very nearly but not exactly equidistant. Variability near 0.0021 c/d was not detected. The long-term frequency stability could be used to derive meaningful constraints on the properties of a putative companion star. The IUE spectra do not reveal the presence of a hot subluminous secondary. $\nu$\,Pup is another Be star exhibiting an NRP variability pattern with long-term constancy and underlining the importance of combination frequencies and frequency groups. The star is a good target for efforts to identify an effectively single Be star.

arXiv comment16 pages, 12 figures, 5 tables, submitted to Astronomy & Astrophysics

References in corpus (60)

• Validation of the new Hipparcos reduction
• The SIMBAD astronomical database
• A Grid of NLTE Line-Blanketed Model Atmospheres of O-type Stars
• Mass loss from hot massive stars
• Be/X-ray binaries
• Classical Be Stars: Rapidly Rotating B Stars with Viscous Keplerian Decretion Disks
• A Catalog of Multiplicity among Bright Stellar Systems
• X-Ray Spectroscopy of Stars
• Effects of gravitational darkening on the determination of fundamental parameters in fast rotating B-type stars
• BRITE-Constellation: nanosatellites for precision photometry of bright stars
• New Periodic Variables from the Hipparcos Epoch Photometry
• Catalog of Galactic Beta Cephei Stars
• Signatures of internal rotation discovered in the Kepler data of five slowly pulsating B stars
• FM stars: A Fourier view of pulsating binary stars, a new technique for measuring radial velocities photometrically
• Kepler observations of variability in B-type stars
• A unifying explanation of complex frequency spectra of gamma Dor, SPB and Be stars: combination frequencies and highly non-sinusoidal light curves
• Effects of metallicity, star-formation conditions, and evolution in B and Be stars. II: Small Magellanic Cloud, field of NGC 330
• Photometric amplitudes and phases of nonradial oscillation in rotating stars
• Dynamical Evolution of Viscous Disks around Be Stars. I: photometry
• Mass loss in main-sequence B stars
• Detection of additional Be+sdO systems from IUE spectroscopy
• Rotational velocities of A-type stars I. Measurement of vsini in the southern hemisphere
• Mass and angular momentum loss via decretion disks
• Fundamental parameters of B Supergiants from the BCD System
• Populations of rotating stars II. Rapid rotators and their link to Be-type stars
• The life cycles of Be viscous decretion discs: fundamental disc parameters of 54 SMC Be stars
• Short-term variability and mass loss in Be stars I. BRITE satellite photometry of $\eta$ and $\mu$ Centauri
• The life cycles of Be viscous decretion discs: time-dependent modelling of infrared continuum observations
• Beyond the Kepler/K2 bright limit: variability in the seven brightest members of the Pleiades
• Spectral and spatial imaging of the Be+sdO binary phi Persei
• The Banana Project. III. Spin-orbit Alignment in the Long-period Eclipsing Binary NY Cephei
• The BRITE Constellation nanosatellite mission: Testing, commissioning and operations
• First spectro-interferometric survey of Be stars I. Observations and constraints on the disks geometry and kinematics
• Be discs in binary systems I. Coplanar orbits
• Detection of the Ultraviolet Spectrum of the Hot Subdwarf Companion of 60 Cygni (B1 Ve) from a Survey of IUE Spectra of Be Stars
• MOST Detects g-Modes in the Late-Type be Star beta CMi (B8Ve)
• On the kinematics of a runaway Be star population
• Achernar: Rapid Polarization Variability as Evidence of Photospheric and Circumstellar Activity
• Dynamical Evolution of Viscous Disks around Be Stars. II : polarimetry
• The Hot Companion and Circumbinary Disk of the Be Star HR 2142
• The life cycles of Be viscous decretion discs: The case of ω CMa
• Stellar variability in open clusters. I. A new class of variable stars in NGC 3766
• BRITE-Constellation: Data processing and photometry
• Be discs in coplanar circular binaries: Phase-locked variations of emission lines
• MOST detects SPBe pulsations in HD 127756 & HD 217543: Asteroseismic rotation rates independent of vsini
• Short-term variability and mass loss in Be stars III. BRITE and SMEI satellite photometry of 28 Cygni
• Short-term variability and mass loss in Be stars II. Physical taxonomy of photometric variability observed by the Kepler spacecraft
• Blazhko effect in the Galactic bulge fundamental mode RR~Lyrae stars I: Incidence rate and differences between modulated and non-modulated stars
• The close-in companion of the fast rotating Be star Achernar
• Pulsations in the late-type Be star HD 50209 detected by CoRoT
• Rotational and Cyclical Variability in gamma Cassiopeia
• Time-series photometry of the O4 I(n)fp star zeta Puppis
• Rotational and Cyclical Variability in gamma Cassiopeiae. II. Fifteen Seasons
• Properties and nature of Be stars: 29. Orbital and long-term spectral variations of γ Cassiopeiæ
• An investigation of the photometric variability of confirmed and candidate Galactic Be stars using ASAS-3 data
• Stellar parameters of Be stars observed with X-shooter
• Variations of the amplitudes of oscillation of the Be star Achernar
• IR nebulae around bright massive stars as indicators for binary interactions
• A representative sample of Be stars V: Hα variability
• Ultraviolet Activity as indicator of Small-scale Magnetic Fields in gamma Cassiopeiae

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• Gaia Data Release 3: Pulsations in main sequence OBAF-type stars
• TESS observations of Be stars: a new interpretation
• Dynamical masses of the primary Be star and the secondary sdB star in the single-lined binary kappa Dra (B6 IIIe)
• Revisiting the pulsational characteristics of the exoplanet host star $\beta$ Pictoris
• TESS lightcurves of gamma-Cas stars
• A Multi-observing-technique Study of the Dynamical Evolution of the Viscous Disk around the Be Star $\omega$ CMa
• TESS observations of Be stars: general characteristics and the impulsive magnetic rotator model
• Let there be more variability in two gamma Cas stars
• Short-term variability and mass loss in Be stars VI. Frequency groups in $\gamma$ Cas detected by TESS
• Optical spectroscopy of Galactic field Classical Be stars
• Space Photometry with BRITE-Constellation
• Fast time optical variability in Be/X-ray binaries. Pulsation and rotation
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