The slowly pulsating B-star 18 Peg: A testbed for upper main sequence stellar evolution

Abstract

The predicted width of the upper main sequence in stellar evolution models depends on the empirical calibration of the convective overshooting parameter. Despite decades of discussions, its precise value is still unknown and further observational constraints are required to gauge it. Based on a photometric and preliminary asteroseismic analysis, we show that the mid B-type giant 18 Peg is one of the most evolved members of the rare class of slowly pulsating B-stars and, thus, bears tremendous potential to derive a tight lower limit for the width of the upper main sequence. In addition, 18 Peg turns out to be part of a single-lined spectroscopic binary system with an eccentric orbit that is greater than 6 years. Further spectroscopic and photometric monitoring and a sophisticated asteroseismic investigation are required to exploit the full potential of this star as a benchmark object for stellar evolution theory.

arXiv comment14 pages, 12 figures, Astronomy and Astrophysics, accepted

References in corpus (23)

• emcee: The MCMC Hammer
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Transiting Exoplanet Survey Satellite
• Correcting for the Effects of Interstellar Extinction
• Grids of stellar models with rotation - I. Models from 0.8 to 120 Msun at solar metallicity (Z = 0.014)
• X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope
• GAIA: Composition, Formation and Evolution of the Galaxy
• Rotating Massive Main-Sequence Stars I: Grids of Evolutionary Models and Isochrones
• Spectral Irradiance Calibration in the Infrared. XIV: the Absolute Calibration of 2MASS
• Automated data reduction workflows for astronomy
• A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
• 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 spectroscopic survey on the multiplicity of high-mass stars
• The Neutron Star Mass Distribution
• A Stellar Rotation Census of B Stars: from ZAMS to TAMS
• Toward Complete Statistics of Massive Binary Stars: Penultimate Results from the Cygnus OB2 Radial Velocity Survey
• Spectrophotometric Libraries, Revised Photonic Passbands and Zero-points for UBVRI, Hipparcos and Tycho Photometry
• Tight asteroseismic constraints on core overshooting and diffusive mixing in the slowly rotating pulsating B8.3V star KIC 10526294
• Fundamental properties of nearby single early B-type stars
• The Impact of Enhanced Iron Opacity on Massive Star Pulsations: Updated Instability Strips
• The Nature of the Hyper-Runaway Candidate HIP 60350
• The Age and Interior Rotation of Stars from Asteroseismology
• Photonic Passbands and Zeropoints for the Stromgren uvby system

Cited by in corpus (14)

• A naked-eye triple system with a nonaccreting black hole in the inner binary
• PG 1610$+$062: a runaway B star challenging classical ejection mechanisms
• $\gamma$ Columbae: the recently stripped, pulsating core of a massive star
• Sub-stellar Companions of Intermediate-mass Stars with CoRoT: CoRoT-34b, CoRoT-35b, and CoRoT-36b
• Radial velocity measurements and orbit determination of eight single-lined spectroscopic binary systems
• An interferometric study of B star multiplicity
• The Radial and Rotational Velocity of $\zeta$ Ophiuchi
• Weak Metallic Emission Lines in Early B-Type Stars
• Identification of young nearby runaway stars based on Gaia data and the lithium test
• Spectroscopic characterization of nine binary star systems as well as HIP107136 and HIP107533
• Spectroscopic orbit determination of the long-periodic binary system $\theta$ Cep
• Highly accurate quantitative spectroscopy of massive stars in the Galaxy
• Commissioning an Inexpensive Off-the-shelf Spectrograph for Radial-Velocity Studies
• Identification of additional young nearby runaway stars based on Gaia data release 2 observations and the lithium test