The distance, rotation, and physical parameters of zeta Pup

Abstract

We scrutinize the Hipparcos parallax for the bright O supergiant zeta Pup, and confirm that the implied distance of 332+/-11pc appears to be reliable. We then review the implications for the star's physical parameters, and the consequences for the interpretation of P(phot), the 1.78-d photometric period. The equatorial rotation period is <3.7d (with 95% confidence), ruling out a proposed ~5.1d value. If the photometric period is the rotation period then i, the inclination of the rotation axis to the line of sight, is 33.2+/-1.8 degrees. The inferred mass, radius, and luminosity are securely established to be less than canonical values for the spectral type, and are not in agreement with single-star evolution models. The runaway status, rapid rotation, and anomalous physical properties are all indicative of an evolutionary history involving binary (or multiple-star) interaction. We perform simple starspot modelling to show that the low axial inclination required if P(rot) = 1.78d has testable spectroscopic consequences, which have not been identified in existing time series. If P(phot) is directly related to drivers of systematic, high-velocity stellar-wind variability (`discrete absorption components') in zeta Pup, antisolar differential rotation is required. Model line profiles calculated on that basis are at variance with observations.

MNRAS, submitted

References in corpus (12)

• UBVJHK synthetic photometry of Galactic O stars
• Bright OB stars in the Galaxy - III. Constraints on the radial stratification of the clumping factor in hot star winds from a combined Halpha, IR and radio analysis
• The stellar association around Gamma Velorum and its relationship with Vela OB2
• BONNSAI: a Bayesian tool for comparing stars with stellar evolution models
• γ^2 Velorum: Orbital Solution and Fundamental Parameter Determination with SUSI
• On the origin of field O-type stars
• Direct constraint on the distance of y2 Velorum from AMBER/VLTI observations
• BRITE-Constellation high-precision time-dependent photometry of the early-O-type supergiant $\zeta$ Puppis unveils the photospheric drivers of its small- and large-scale wind structures
• MOST detects corotating bright spots on the mid-O type giant ξ Persei
• Radial dependence of line profile variability in seven O9--B0.5 stars
• Time-series photometry of the O4 I(n)fp star zeta Puppis
• Mid-infrared observations of O-type stars: spectral morphology

Cited by in corpus (11)

• The Formation of a Stellar Association in the NGC 7000/IC 5070 Complex: Results from Kinematic Analysis of Stars and Gas
• Far UV and Optical Emissions from Three Very Large Supernova Remnants Located at Unusually High Galactic Latitudes
• Correlated X-ray and optical variability in the O-type supergiant zeta Puppis
• Chandra grating spectroscopy of embedded wind shock X-ray emission from O stars shows low plasma temperatures and significant wind absorption
• The spin rates of O stars in WR + O Magellanic Cloud binaries
• Modeling Magnetically Channeled Winds in 3D: I. Isothermal Simulations of a Magnetic O Supergiant
• TESS photometry of helium-rich hot subdwarfs: r modes in BD+37 442 and BD+37 1977
• Helium-like X-ray line complexes show that the hottest plasma on the O supergiant zeta Puppis is in its wind
• Testing the Reliability of X-rays as a Tool for Constraining Mass-loss Rates of Hot Stars
• Observed epochal variations in X-ray lines from the O Supergiant $\zeta$ Puppis do not require substantial changes in the wind mass flux
• CoronaGraph Instrument Reference stars for Exoplanets (CorGI-REx) I. Preliminary Vetting and Implications for the Roman Coronagraph and Habitable Worlds Observatory