Constraining Mass Transfer Histories of Blue Straggler Stars with COS Spectroscopy of White Dwarf Companions

Abstract

Recent studies show that the majority of blue straggler stars (BSSs) in old open clusters are formed through mass transfer from an evolved star onto a main-sequence companion, resulting in a BSS and white dwarf (WD) in a binary system. We present constraints on the mass transfer histories of two BSS-WD binaries in the open cluster NGC 188, using WD temperatures and surface gravities measured with HST COS far-ultraviolet spectroscopy. Adopting a Gaia-based cluster distance of $1847\pm 107$ pc, we determine that one system, WOCS 4540, formed through Case C mass transfer resulting in a CO-core white dwarf with $T_{\text{eff}}=17000_{-200}^{+140}$ K and a $\log g=7.80_{-0.06}^{+0.06}$, corresponding to a mass of $0.53_{-0.03}^{+0.03}$ $M_{\odot }$ and a cooling age of $105_{-5}^{+6}$ Myr. The other system, WOCS 5379, formed through Case B mass transfer resulting in a He-core white dwarf with $T_{\text{eff}}=15500_{-150}^{+170}$ K and a $\log g=7.50_{-0.05}^{+0.06}$, corresponding to a mass of $0.42_{-0.02}^{+0.02}$ $M_{\odot }$ and an age of $250_{-20}^{+20}$ Myr. The WD parameters are consistent across four different cluster distance assumptions. We determine possible progenitor binary systems with a grid of accretion models using MESA, and investigate whether these systems would lead to stable or unstable mass transfer. WOCS 4540 likely resulted from stable mass transfer during periastron passage in an eccentric binary system, while WOCS 5379 challenges our current understanding of the expected outcomes for mass transfer from red giant branch stars. Both systems are examples of the value in using detailed analyses to fine-tune our physical understanding of binary evolutionary processes.

arXiv comment16 pages, 10 figures, 2 tables, submitted to Astrophysical Journal

References in corpus (50)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• The NumPy array: a structure for efficient numerical computation
• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• Evolution of binary stars and the effect of tides on binary populations
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• Common Envelope Evolution: Where we stand and how we can move forward
• A Gaia DR2 view of the Open Cluster population in the Milky Way
• A standard stellar library for evolutionary synthesis: II. The M dwarf extension
• On the use of empirical bolometric corrections for stars
• An Improved Spectroscopic Analysis of DA White Dwarfs from the Sloan Digital Sky Survey Data Release 4
• On the triple origin of blue stragglers
• New evolutionary sequences for extremely low mass white dwarfs: Homogeneous mass and age determinations, and asteroseismic prospects
• The astrometric core solution for the Gaia mission. Overview of models, algorithms and software implementation
• Mergers and Obliquities in Stellar Triples
• Relative Frequencies of Blue Stragglers in Galactic Globular Clusters: Constraints for the Formation Mechanisms
• Detached white dwarf main-sequence star binaries
• Wind Roche-lobe overflow: Application to carbon-enhanced metal-poor stars
• Low and intermediate-mass close binary evolution and the initial - final mass relation
• Mass Transfer from Giant Donors
• Evolution of Stellar Collision Products in Globular Clusters - II. Off-axis Collision
• Mass loss on the red giant branch: the value and metallicity dependence of Reimers' η in globular clusters
• Testing the white dwarf mass-radius relationship with eclipsing binaries
• Mass transfer from a giant star to a main sequence companion and its contribution to long-orbital-period blue stragglers
• A mass transfer origin for blue stragglers in NGC 188 as revealed by half-solar-mass companions
• Orbital eccentricities of binary systems with a former AGB star
• KOI-3278: A Self-Lensing Binary Star System
• Implications for the Formation of Blue Straggler Stars from HST Ultraviolet Observations of NGC 188
• Age and distance for the old open cluster NGC188 from the eclipsing binary member V12
• Detection of white dwarf companions to blue stragglers in the open cluster NGC 188: direct evidence for recent mass transfer
• Blue Lurkers: Hidden Blue Stragglers on the M67 Main Sequence Identified from their Kepler/K2 Rotation Periods
• On the Origin of Sub-subgiant Stars. I. Demographics
• Can We Trust Models for Adiabatic Mass Loss?
• Stellar Exotica in 47 Tucanae
• Acoustic Signatures of the Helium Core Flash
• Binary Blue Metal-Poor Stars: Evidence for AGB Mass Transfer
• S1040 in M67: A Post-Mass-Transfer Binary with a Helium-Core White Dwarf
• An analytic model for mass transfer in binaries with arbitrary eccentricity, with applications to triple-star systems
• WIYN Open Cluster Study. XXXVI. Spectroscopic Binary Orbits in NGC 188
• Discovery of three self-lensing binaries from Kepler
• An Analytic Model for Blue Straggler Formation in Globular Clusters
• Very low mass white dwarfs with a C-O core
• The core helium flash revisited III. From Pop I to Pop III stars
• The Blue Stragglers of the Old Open Cluster NGC 188
• The White Dwarf Companions of 56 Per and HR 3643
• Star Cluster Ages in the Gaia Era
• Binary Evolution: Roche Lobe Overflow and Blue Stragglers

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• WIYN Open Cluster Study. LXXXVII. HST Ultraviolet Detection of Hot White Dwarf Companions to Blue Lurkers in M67
• UOCS.VI. UVIT/AstroSat detection of low-mass white dwarf companions to 4 more blue stragglers in M67
• The White Dwarf Binary Pathways Survey -- IX. Three long period white dwarf plus subgiant binaries
• Spectroscopic Detection of the Pre-White Dwarf Companion of Regulus
• WOCS 4540: Detailed Analysis of a Very Long Orbital Period Blue Straggler
• Blue Stragglers and Friends: Initial Evolutionary Pathways in Close Low-Mass Binaries: Literature Review
• Formation and Evolution of Accreting Compact Objects
• The Blue Lurker WOCS 14020: A Long-Period Post-Common-Envelope Binary in M67 Originating from a Merger in a Triple System
• Photometric variability of blue straggler stars in M67 with TESS and K2
• On rare core collapse supernovae inside planetary nebulae
• Variable Blue Straggler Stars in Open Cluster NGC 6819 Observed in the Kepler 'Superstamp' Field
• Taking apart the dynamical clock. Fat-tailed dynamical kicks shape the blue-straggler star bimodality