The timescale of low-mass proto-helium white dwarf evolution

  title={The timescale of low-mass proto-helium white dwarf evolution},
  author={A G Istrate and Thomas M Tauris and Norbert Langer and John Antoniadis},
  journal={Astronomy and Astrophysics},
Context. A large number of low-mass (<∼0.20 M ) helium white dwarfs (He WDs) have recently been discovered. The majority of these are orbiting another WD or a millisecond pulsar (MSP) in a close binary system; a few examples are found to show pulsations or to have a main-sequence star companion. There appear to be discrepancies between the current theoretical modelling of such lowmass He WDs and a number of key observed cases, indicating that their formation scenario yet remains to be fully… Expand

Figures and Tables from this paper

The formation of low-mass helium white dwarfs orbiting pulsars: Evolution of low-mass X-ray binaries below the bifurcation period
Millisecond pulsars (MSPs) are generally believed to be old neutron stars (NSs) which have been spun up to high rotation rates via accretion of matter from a companion star in a low-mass X-ray binaryExpand
Novel modelling of ultracompact X-ray binary evolution - stable mass transfer from white dwarfs to neutron stars
Tight binaries of helium white dwarfs (He WDs) orbiting millisecond pulsars (MSPs) will eventually "merge" due to gravitational damping of the orbit. The outcome has been predicted to be theExpand
Models of low-mass helium white dwarfs including gravitational settling, thermal and chemical diffusion, and rotational mixing
A large number of extremely low-mass helium white dwarfs (ELM WDs) have been discovered in recent years. The majority of them are found in close binary systems suggesting they are formed eitherExpand
An eccentric binary millisecond pulsar with a helium white dwarf companion in the Galactic Field
Low-mass white dwarfs (LMWDs) are believed to be exclusive products of binary evolution, as the Universe is not yet old enough to produce them from single stars. Because of the strong tidal forcesExpand
A Model of the Pulsating Extremely Low-Mass White Dwarf Precursor WASP 0247-25B
We present an analysis of the evolutionary and pulsation properties of the extremely low-mass white dwarf precursor (B) component of the double-lined eclipsing system WASP 0247-25. Given that theExpand
The evolution of white dwarfs resulting from helium-enhanced, low-metallicity progenitor stars
Context. Some globular clusters host multiple stellar populations with different chemical abundance patterns. This is particularly true for ? Centauri, which shows clear evidence of a helium-enrichedExpand
New full evolutionary sequences of H- and He-atmosphere massive white dwarf stars using MESA
We explore the evolution of hydrogen-rich and hydrogen-deficient white dwarf stars with masses between 1.012 and 1.307 Msun, and initial metallicity of Z=0.02. These sequences are the result of mainExpand
An Extremely Low-mass He White Dwarf Orbiting the Millisecond Pulsar J1342+2822B in the Globular Cluster M3
We report on the discovery of the companion star to the millisecond pulsar J1342+2822B in the globular cluster M3. We exploited a combination of near-ultraviolet and optical observations acquiredExpand
On the Formation of Eccentric Millisecond Pulsars with Helium White-dwarf Companions
Millisecond pulsars (MSPs) orbiting helium white dwarfs (WDs) in eccentric orbits challenge the established binary-evolution paradigm that predicts efficient orbital circularization during theExpand
The Formation of Subdwarf A-type Stars
Subdwarf A-type stars (sdAs) are objects that have hydrogen-rich spectra with surface gravity similar to that of hot subdwarf stars but effective temperature below the zero-age horizontal branchExpand


The formation of low-mass helium white dwarfs orbiting pulsars: Evolution of low-mass X-ray binaries below the bifurcation period
Millisecond pulsars (MSPs) are generally believed to be old neutron stars (NSs) which have been spun up to high rotation rates via accretion of matter from a companion star in a low-mass X-ray binaryExpand
Cooling curves and initial models for low-mass white dwarfs (<0.25 M⊙) with helium cores
We present a detailed calculation of the evolution of low-mass (<0.25 M⊙) helium white dwarfs. These white dwarfs (the optical companions to binary millisecond pulsars) are formed via long-term,Expand
The Masses of the Millisecond Pulsar J1012+5307 and Its White Dwarf Companion
We report on spectroscopy of the white dwarf companion of the millisecond radio pulsar PSR J1012+5307. We find strong Balmer absorption lines, as would be expected for a cool DA white dwarf. TheExpand
Timing of a young mildly recycled pulsar with a massive white dwarf companion
We report on timing observations of the recently discovered binary pulsar PSR J1952+2630 using the Arecibo Observatory. The mildly recycled 20.7-ms pulsar is in a 9.4-hr orbit with a massive, MW D >Expand
We present the results of a systematic study of the evolution of low- and intermediate-mass X-ray binaries (LMXBs and IMXBs). Using a standard Henyey-type stellar evolution code and a standard modelExpand
Most millisecond pulsars with low-mass companions are in systems with either helium-core white dwarfs or non-degenerate ("black widow" or "redback") stars. A candidate counterpart to PSR J1816+4510Expand
Formation of millisecond pulsars with CO white dwarf companions – II. Accretion, spin-up, true ages and comparison to MSPs with He white dwarf companions
Millisecond pulsars are mainly characterized by their spin periods, B-fields and masses – quantities that are largely affected by previous interactions with a companion star in a binary system. InExpand
Evolutionary Properties of Helium-rich, Degenerate Dwarfs in Binaries Containing Compact Companions
The evolution of binaries containing low-mass donors (� 2 M� ) and degenerate accretors (i.e., white dwarfs [0.7 M� ]o r neutron stars [1.4M� ]) is systematically investigated over a wide expanse ofExpand
The impact of element diffusion on the formation and evolution of helium white dwarf stars
The aim of this work is to investigate the effect of element diffusion on the evolution of helium white dwarfs. To this end, we couple the multicomponent flow equations that describe gravitationalExpand
We analyze radial velocity observations of the 12 extremely low-mass (ELM), with {<=}0.25 M{sub sun}, white dwarfs (WDs) in the MMT Hypervelocity Star Survey. Eleven of the twelve WDs are binariesExpand