MOST Detects g- and p-Modes in the B Supergiant HD 163899 (B2 Ib/II)

@article{Saio2006MOSTDG,
  title={MOST Detects g- and p-Modes in the B Supergiant HD 163899 (B2 Ib/II)},
  author={Hideyuki Saio and Rainer Kuschnig and A. Gautschy and Chris Cameron and Gordon Arthur Hunter Walker and Jaymie Matthews and David B. Guenther and Anthony F. J. Moffat and Slavek M. Rucinski and Dimitar D. Sasselov and Werner W. Weiss},
  journal={The Astrophysical Journal},
  year={2006},
  volume={650},
  pages={1111-1118}
}
The Microvariability and Oscillations of Stars (MOST) satellite observed the B supergiant HD 163899 (B2 Ib/II) for 37 days as a guide star and detected 48 frequencies P2.8 cycles day � 1 with amplitudes of a few millimagnitudes (mmag) and less. The frequency range embraces g- and p-mode pulsations. It was generally thought that no g-modes are excited in less luminous B supergiants because strong radiative damping is expected in the core. Our theoretical models, however, show that such g-modes… 
MOST Detects g-Modes in the Late-Type Be Star β Canis Minoris (B8 Ve)
The Microvariability and Oscillations of Stars (MOST) satellite has detected low-amplitude light variations (?m ~ 1 mmag) in the Be star ? CMi (B8 Ve). The observations lasted 41 days and the
MOST Detects SPBe Pulsations in HD 127756 and HD 217543: Asteroseismic Rotation Rates Independent of vsini
The MOST (Microvariability and Oscillations of Stars ) satellite has discovered SPBe (slowly pulsating Be)
Excitation of pulsation modes in B-type supergiant stars
We present results on the instability analysis of the post main sequence massive star models against radial and nonradial pulsations. Both p- and g-modes can be excited by the κ-mechanism operating
Effect of mass loss on the driving of g-modes in B supergiant stars
MOST has detected p and g-modes in the B supergiant star HD163899. Saio et al. (2006) have explained the driving of g-modes in a post main sequence star by the presence of a convective shell which
Revising the Evolutionary Stage of HD 163899: The Effects of Convective Overshooting and Rotation
We revise the evolutionary status of the B-type supergiant HD\,163899 based on the new determinations of the mass-luminosity ratio, effective temperature and rotational velocity as well as on the
Progress and problems in massive star pulsation theory
Abstract Massive stars pulsate in various modes; radial and nonradial p-modes, g-modes, and strange modes including oscillatory convective (non-adiabatic g−) modes. Those modes are responsible for
Pulsational instability in B-type supergiant stars
We present results of the instability analysis of the post-main sequence massive star models against radial and nonradial pulsations. We confirm that both p- and g-modes can be excited by the
Detection of a 1.59 h period in the B supergiant star HD 202850
Context. Photospheric lines of B-type supergiants show variability in their profile shapes. In addition, their widths are much wider than can be accounted for purely by stellar rotation. This excess
Radial and nonradial oscillations of massive supergiants
  • H. Saio
  • Physics
    Proceedings of the International Astronomical Union
  • 2010
Abstract Stability of radial and nonradial oscillations of massive supergiants is discussed. The kappa-mechanism and strange-mode instability excite oscillations having various periods in wide ranges
Confirmation of simultaneous p and g mode excitation in HD 8801 and γ Peg from time-resolved multicolour photometry of six candidate ‘hybrid’ pulsators
We carried out a multicolour time-series photometric study of six stars claimed as 'hybrid' p and g mode pulsators in the literature. γ Peg was confirmed to show short-period oscillations of the β
...
...

References

SHOWING 1-10 OF 27 REFERENCES
MOST Detects g-Modes in the Be Star HD 163868*
We have extracted a 37 day light curve with a precision of 0.0012 mag per point for the Microvariability and Oscillations of Stars (MOST) guide star, HD 163868 (B5 Ve). Its rich frequency spectrum
The opacity mechanism in B-type stars – II. Excitation of high-order g-modes in main-sequence stars
We show that the OPAL opacities, in addition to explaining the origin of the pulsations of β Cep stars, also predict the existence of a large region in the main-sequence band at lower luminosities,
Discovery of the New Slowly Pulsating B Star HD 163830 (B5 II/III) from MOST Space-based Photometry
We report the discovery of a new slowly pulsating B star, with the largest number of detected frequencies to date by more than a factor of 3, based on 37 days of MOST (Microvariability and
Pulsations of the Oe Star ζ Ophiuchi from MOST Satellite Photometry and Ground-based Spectroscopy
Twenty-four days of highly precise Microvariability and Oscillations of Stars (MOST) satellite photometry obtained in mid-2004 of the rapidly rotating O9.5 V star ζ Oph have yielded at least a dozen
On non-radial oscillations of B-type stars.
The excitation mechanisms behind the slow pulsations―with periods of the order of one day―of OB stars are discussed on the basis of numerical computations. Non-radial, non-adiabatic stability
Multi-periodic photospheric pulsations and connected wind structures in HD 64760
We report on the results of an extended optical spectroscopic monitoring campaign on the early-type B supergiant HD64760 (B0.5Ib) designed to probe the deep-seated origin of spatial wind structure in
The stability of massive stars and its dependence on metallicity and opacity
Following a similar investigation based on the of LAOL opacities, the stability of massive stars is re-examined using the latest available OPAL opacity tables. Two groups of dynamical strange-mode
δ Ceti Is Not Monoperiodic: Seismic Modeling of a β Cephei Star from MOST* Space-based Photometry
The β Cephei star δ Ceti was considered one of the few monoperiodic variables in its class. Despite (or perhaps because of) its apparently simple oscillation spectrum, it has been challenging and
Linear, nonadiabatic analysis of nonradial oscillations of massive near main sequence stars
The equations for linear, nonadiabatic, nonradial oscillations have been solved for models with 7 M/sub sun/, 12 M/sub sun/, and 20 M/sub sun/ in the core-hydrogen burning and hydrogen exhaustion
HIPPARCOS photometry of 24 variable massive stars (alpha Cygni variables)
The photometric variability of 24 Cyg vari- ables, i.e. variable super{and hypergiants, observed by the Hipparcos satellite is described. Three of the selected stars are situated in the SMC, 12 in
...
...