HIP 15429: A newborn Be star on an eccentric binary orbit

Abstract

We identified a new post-interaction binary, HIP 15429, consisting of a stripped star and a recently formed, rapidly rotating Be star companion ($v\sin i\approx 270$ km/s) sharing many similarities with recently identified bloated stripped stars. From orbital fitting of multi-epoch radial velocities we find a 221-day period. We also find an eccentricity of $e=0.52$, which is unexpectedly high as tides are expected to have circularised the orbit efficiently during the presumed recent mass transfer. The formation of a circumbinary disk during the mass transfer phase or the presence of an unseen tertiary companion might explain the orbit's high eccentricity. We determined physical parameters for both stars by fitting the spectra of the disentangled binary components and multi-band photometry. The stripped nature of the donor star is affirmed by its high luminosity at a low inferred mass ($\lesssim 1{\mathrm{M}}_{\odot }$) and imprints of CNO-processed material in the surface abundances. The donor's relatively large radius and cool temperature ($T_{\mathrm{eff}}=13.5\pm 0.5$ kK) suggest that it has only recently ceased mass transfer. Evolutionary models assuming a 5-6 ${\mathrm{M}}_{\odot }$ progenitor can reproduce these parameters and imply that the binary is currently evolving towards a stage where the donor becomes a subdwarf orbiting a Be star. The remarkably high eccentricity of HIP 15429 challenges standard tidal evolution models, suggesting either inefficient tidal dissipation or external influences, such as a tertiary companion or circumbinary disk. This underscores the need to identify and characterise more post-mass transfer binaries to benchmark and refine theoretical models of binary evolution.

19 pages, 16 figures, accepted for publication in Astronomy & Astrophysics

References in corpus (114)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Modules for Experiments in Stellar Astrophysics (MESA)
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Correcting for the Effects of Interstellar Extinction
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
• Binary interaction dominates the evolution of massive stars
• Modules for Experiments in Stellar Astrophysics (MESA): Convective Boundaries, Element Diffusion, and Massive Star Explosions
• The Swift Ultra-Violet/Optical Telescope
• MESA Isochrones and Stellar Tracks (MIST) 0: Methods for the construction of stellar isochrones
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• Low Temperature Opacities
• Mind your Ps and Qs: the Interrelation between Period (P) and Mass-ratio (Q) Distributions of Binary Stars
• REBOUND: An open-source multi-purpose N-body code for collisional dynamics
• The Eccentric Kozai-Lidov Effect and Its Applications
• The Origin of Subdwarf B Star (I): the Formation Channels
• The chemical make-up of the Sun: A 2020 vision
• IAS15: A fast, adaptive, high-order integrator for gravitational dynamics, accurate to machine precision over a billion orbits
• The origin of sdB stars (II)
• Shell-model calculations of stellar weak interaction rates: II. Weak rates for nuclei in the mass range A=45-65 in supernovae environment
• A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
• VOSA: Virtual Observatory SED Analyzer. An application to the Collinder 69 open cluster
• Modules for Experiments in Stellar Astrophysics (MESA): Time-Dependent Convection, Energy Conservation, Automatic Differentiation, and Infrastructure
• Classical Be Stars: Rapidly Rotating B Stars with Viscous Keplerian Decretion Disks
• The rotation rates of massive stars: the role of binary interaction through tides, mass transfer and mergers
• The High Angular Resolution Multiplicity of Massive Stars
• Observed Fractions of Core-Collapse Supernova Types and Initial Masses of their Single and Binary Progenitor Stars
• GYRE: An open-source stellar oscillation code based on a new Magnus Multiple Shooting Scheme
• HERMES: a high-resolution fibre-fed spectrograph for the Mercator telescope
• Updated Electron-Conduction Opacities: The Impact on Low-Mass Stellar Models
• A million binaries from Gaia eDR3: sample selection and validation of Gaia parallax uncertainties
• The California Planet Survey I. Four New Giant Exoplanets
• ADIPLS -- the Aarhus adiabatic oscillation package
• HAT-P-16b: A 4 Mj Planet Transiting A Bright Star On An Eccentric Orbit
• Physical Parameters and Wind Properties of Galactic Early B Supergiants
• Be-star rotation: how close to critical?
• Theoretical light curves for deflagration models of Type Ia supernova
• Gaia Data Release 3: Stellar multiplicity, a teaser for the hidden treasure
• Thermodynamic functions of dense plasmas: analytic approximations for astrophysical applications
• A statistical test for Nested Sampling algorithms
• The VLT-FLAMES Tarantula Survey XII. Rotational velocities of the single O-type stars
• The evolution of runaway stellar collision products
• Collaborative Nested Sampling: Big Data vs. complex physical models
• Forming short-period Wolf-Rayet X-ray binaries and double black holes through stable mass transfer
• Angular momentum transport by heat-driven g-modes in slowly pulsating B stars
• Spectral models for binary products: Unifying Subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars
• A wide star-black-hole binary system from radial-velocity measurements
• Gaia Data Release 3: External calibration of BP/RP low-resolution spectroscopic data
• Coulomb tunneling for fusion reactions in dense matter: Path integral Monte Carlo versus mean field
• Different to the core: the pre-supernova structures of massive single and binary-stripped stars
• On the consistent treatment of the quasi-hydrostatic layers in hot star atmospheres
• The VLT-FLAMES Tarantula Survey X: Evidence for a bimodal distribution of rotational velocities for the single early B-type stars
• Common envelope ejection in massive binary stars - Implications for the progenitors of GW150914 and GW151226
• The 'hidden' companion in LB-1 unveiled by spectral disentangling
• Constraining mixing in massive stars in the Small Magellanic Cloud
• Skye: A Differentiable Equation of State
• Hot subdwarf binaries from the MUCHFUSS project - Analysis of 12 new systems and a study of the short-period binary population
• The massive star binary fraction in young open clusters I. NGC 6231 revisited
• Orbital properties of binary post-AGB stars
• Detection of additional Be+sdO systems from IUE spectroscopy
• Is HR 6819 a triple system containing a black hole? -- An alternative explanation
• Spectroscopic analysis of southern B and Be stars
• The impact of stars stripped in binaries on the integrated spectra of stellar populations
• The chemical composition of the Orion star-forming region. III. C, N, Ne, Mg and Fe abundances in B-type stars revisited
• A naked-eye triple system with a nonaccreting black hole in the inner binary
• Orbital eccentricities of binary systems with a former AGB star
• The Detection and Characterization of Be+sdO Binaries from HST/STIS FUV Spectroscopy
• Orbital Evolution of Binaries in Circumbinary Disks
• Massive donors in interacting binaries: effect of metallicity
• PoWR grids of non-LTE model atmospheres for OB-type stars of various metallicities
• Investigating the lack of main-sequence companions to massive Be stars
• Rosseland and flux mean opacities for Compton scattering
• FUV Detection of the Suspected Subdwarf Companion to the Be Star 59 Cygni
• New Conductive Opacities for White Dwarf Envelopes
• Not so fast: LB-1 is unlikely to contain a 70 $M_{\odot }$ black hole
• Spectral and spatial imaging of the Be+sdO binary phi Persei
• The orbits of subdwarf-B + main-sequence binaries. II. Three eccentric systems; BD+29 3070, BD +34 1543 and Feige 87
• Detection of a Hot Subdwarf Companion to the Be Star FY Canis Majoris
• A stripped-companion origin for Be stars: clues from the putative black holes HR 6819 and LB-1
• Coping with loss: Stability of mass transfer from post-main sequence donor stars
• The orbits of subdwarf-B + main-sequence binaries: III. The period - eccentricity distribution
• Testing eccentricity pumping mechanisms to model eccentric long period sdB binaries with MESA
• The orbits of subdwarf B + main-sequence binaries. I: The sdB+G0 system PG 1104+243
• On the use of the Fourier Transform to determine the projected rotational velocity of line-profile variable B stars
• The Tarantula Massive Binary Monitoring VI: Characterisation of hidden companions in 51 single-lined O-type binaries, a flat mass-ratio distribution, and black-hole binary candidates
• A stripped helium star in the potential black hole binary LB-1
• Common envelope evolution of eccentric binaries
• A population of transition disks around evolved stars: Fingerprints of planets? Catalog of disks surrounding Galactic post-AGB binaries
• PG1018-047: the longest period subdwarf B binary
• High resolution spectroscopy of bright subdwarf B stars - I. Radial velocity variables
• Type Ia Supernova models: latest developments
• The Remarkable Be+sdOB Binary HD 55606 I: Orbital and Stellar Parameters
• On rapid binary mass transfer -- I. Physical model
• The Parkes multibeam pulsar survey: VII. Timing of four millisecond pulsars and the underlying spin period distribution of the Galactic millisecond pulsar population
• Long-term Evolution of Binary Orbits Induced by Circumbinary Disks
• Population Synthesis of Galactic Be-star Binaries with A Helium-star Companion
• The orbital and physical properties of five southern Be+sdO binary systems
• Dynamical masses of the primary Be star and the secondary sdB star in the single-lined binary kappa Dra (B6 IIIe)
• Wide post-common envelope binaries from Gaia: orbit validation and formation models
• A partially stripped massive star in a Be binary at low metallicity: A missing link towards Be X-ray binaries and double neutron star mergers
• The earliest O-type eclipsing binary in the Small Magellanic Cloud, AzV 476: A comprehensive analysis reveals surprisingly low stellar masses
• The B-type Binaries Characterisation Programme II. VFTS 291: A stripped star from a recent mass transfer phase
• Two New Long-Period Hot Subdwarf Binaries with Dwarf Companions
• X-Shooting ULLYSES: Massive Stars at low metallicity VIII. Stellar and wind parameters of newly revealed stripped stars in Be binaries
• On the evolutionary nature of puffed-up stripped star binaries and their occurrence in stellar populations
• Validation of Gaia DR3 orbital and acceleration solutions with hierarchical triples
• Autonomous Disentangling for Spectroscopic Surveys

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