The McDonald Accelerating Stars Survey (MASS): White Dwarf Companions Accelerating the Sun-like Stars 12 Psc and HD 159062

Abstract We construct from Gaia eDR3 an extensive catalog of spatially resolved binary stars within ≈ 1 kpc of the Sun, with projected separations ranging from a few au to 1 pc. We estimate the probability that each pair is a chance alignment empirically, using the Gaia catalog itself to calculate the rate of chance alignments as a function of observables. The catalog contains 1.3 (1.1) million binaries with >90% (>99%) probability of being bound, including 16,000 white dwarf – main sequence (WD+MS) binaries and 1,400 WD+WD binaries. We make the full catalog publicly available, as well as the queries and code to produce it. We then use this sample to calibrate the published Gaia DR3 parallax uncertainties, making use of the binary components’ near-identical parallaxes. We show that these uncertainties are generally reliable for faint stars (G ≳ 18), but are underestimated significantly for brighter stars. The underestimates are generally $\le 30\%$ for isolated sources with well-behaved astrometry, but are larger (up to ∼80%) for apparently well-behaved sources with a companion within ≲ 4 arcsec, and much larger for sources with poor astrometric fits. We provide an empirical fitting function to inflate published σϖ values for isolated sources. The public catalog offers wide ranging follow-up opportunities: from calibrating spectroscopic surveys, to precisely constraining ages of field stars, to the masses and the initial-final mass relation of white dwarfs, to dynamically probing the Galactic tidal field.

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Diamonds in the Sky!

The Cosmic Mystery Tour ◽

10.1093/oso/9780198831860.003.0013 ◽

2019 ◽

pp. 101-109

Author(s):

Nicholas Mee

Keyword(s):

Nuclear Fuel ◽

White Dwarf ◽

White Dwarfs ◽

Star Trek ◽

The Sun ◽

New Class ◽

The Earth ◽

Night Sky

After consuming their nuclear fuel, most stars lose their outer envelopes and all that remains is the collapsed core of the star, an object known as a white dwarf. Ever since Galileo pointed a telescope at the night sky, each advance in telescope making has resulted in sensational discoveries. Alvan Clark & Sons ground some of the biggest telescope lenses ever made. Alvan Graham Clark discovered Sirius B while testing one of these lenses. Eddington deduced that Sirius B has a size similar to that of the Earth, but with the mass of the Sun, and was an example of a new class of stars—white dwarfs. The easiest white dwarf to see with a telescope orbits the star Keid. In Star Trek, the planet Vulcan orbits the star Keid A.

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White Dwarf Seismology: Inverse Problem of g-Mode Oscillations

International Astronomical Union Colloquium ◽

10.1017/s0252921100093490 ◽

1988 ◽

Vol 108 ◽

pp. 86-87

Author(s):

Hiromoto Shibahashi ◽

Takashi Sekii ◽

Steven Kawaler

Keyword(s):

Inverse Problem ◽

Internal Structure ◽

White Dwarf ◽

White Dwarfs ◽

Research Field ◽

The Sun ◽

Pulsating Stars ◽

Low Degree ◽

Physical Quantities ◽

Light Variability

Since light variability in white dwarfs was first discovered twenty years ago, eighteen DA white dwarfs, several pulsating DB white dwarfs, and hotter pre-white dwarfs have so far been found to be pulsating variables. The most conspicuous characteristics of pulsations in these stars are that they seem to consist of multiple g-modes of nonradial oscillations. Attention should be paid to multiplicity of modes. Stimulated by the success of helioseimology, a research field called ‘asteroseismology’, in which we may probe the internal structure of stars by means of observations of their oscillations, is going to develop. How well such a seismological approach succeeds is dependent on how many modes are observed in each of stars. Since the number of modes of an individual pulsating white dwarf is larger than those of other types of pulsating stars but for the Sun, the seismological study may be the most promising as to the white dwarfs. In fact, by applying the asymptotic relations among eigenfrequencies of high order g-modes with low degree, the degreel, and the radial ordern, Kawaler(1987a,b,c) succeeded to get some constraints on the physical quantities of some of pulsating white dwarfs.

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Seismic Inversions for White Dwarf Stars

International Astronomical Union Colloquium ◽

10.1017/s025292110001722x ◽

2002 ◽

Vol 185 ◽

pp. 606-607

Author(s):

M. Takata ◽

M.H. Montgomery

Keyword(s):

White Dwarf ◽

White Dwarfs ◽

The Sun ◽

Dwarf Stars ◽

White Dwarf Stars ◽

Inversion Methods ◽

Space Observations

AbstractInversion methods have been used successfully for the Sun. The stars with the next richest set of observed frequencies are the white dwarfs. We consider here the viability of numerical inversions for these stars. We find that, while the number of presently observed modes in the white dwarf GD 358 is too small for structural inversions, such inversions would be possible if the frequencies of all modes with 1 ≤ l ≤ 3 were observed. This is possible for space observations by e.g. Eddington.

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The Elemental Compositions of Extrasolar Planetesimals

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313012878 ◽

2012 ◽

Vol 8 (S293) ◽

pp. 219-228 ◽

Cited By ~ 2

Author(s):

M. Jura

Keyword(s):

White Dwarf ◽

Building Blocks ◽

Small Sample ◽

Ultraviolet Spectroscopy ◽

The Sun ◽

Zeroth Order ◽

Dwarf Stars ◽

Heavy Atoms ◽

White Dwarf Stars ◽

Rocky Planets

AbstractEvidence is now compelling that most externally-polluted white dwarfs derive their heavy atoms by accretion from asteroids – the building blocks of rocky planets. Optical and ultraviolet spectroscopy of a small sample of suitable white dwarf stars shows that to zeroth order, the accreted extrasolar parent bodies compositionally resemble bulk Earth. (1) Extrasolar planetesimals are at least 85% by mass composed of O, Mg, Si and Fe. (2) Compared to the Sun, C is often deficient, usually by at least a factor of 10 and therefore comprises less than 1% of an extrasolar planetesimal's mass. At least to-date, C has never been found to be enhanced as would be expected if carbon-rich planetesimals have formed. (3) While there may be individual exceptions, considered as a whole, the population of extrasolar asteroids accreted onto a well-defined sample of local white dwarf stars is less than 1% water by mass.

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Search for (sub)stellar Companions of Exoplanet Hosts by Exploring the Second ESA-Gaia Data Release

Frontiers in Astronomy and Space Sciences ◽

10.3389/fspas.2021.624907 ◽

2021 ◽

Vol 8 ◽

Author(s):

K.-U. Michel ◽

M. Mugrauer

Keyword(s):

White Dwarf ◽

Proper Motion ◽

Brown Dwarfs ◽

The Sun ◽

Data Release ◽

Gravitational Stability ◽

Using Data ◽

Triple Star ◽

Gaia Dr2

We present the latest results of an ongoing multiplicity survey of exoplanet hosts, which was initiated at the Astrophysical Institute and University Observatory Jena, using data from the second data release of the ESA-Gaia mission. In this study the multiplicity of 289 targets was investigated, all located within a distance of about 500 pc from the Sun. In total, 41 binary, and five hierarchical triple star systems with exoplanets were detected in the course of this project, yielding a multiplicity rate of the exoplanet hosts of about 16%. A total of 61 companions (47 stars, a white dwarf, and 13 brown dwarfs) were detected around the targets, whose equidistance and common proper motion with the exoplanet hosts were proven with their precise Gaia DR2 astrometry, which also agrees with the gravitational stability of most of these systems. The detected companions exhibit masses from about 0.016 up to 1.66 M⊙ and projected separations in the range between about 52 and 9,555 au.

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Structure and Composition of White Dwarf Atmospheres and Convection Zones

International Astronomical Union Colloquium ◽

10.1017/s0252921100075977 ◽

1979 ◽

Vol 53 ◽

pp. 223-244

Author(s):

K.H. Böhm

Keyword(s):

White Dwarf ◽

White Dwarfs ◽

Energy Transport ◽

Practical Interest ◽

Surface Flux ◽

Surface Fluxes ◽

The Sun ◽

Surface Cooling ◽

Additional Energy ◽

Basic Properties

SummaryWe present a brief review of the basic properties of white dwarf atmospheres) convection zones and corona models emphasizing qualitative and intuitive aspects.1. Atmospheres: We restrict our discussion essentially to very hot and very cool atmospheres since these are especially interesting. With regard to the first type of objects we study the fundamental differences between DA and non-DA models and between their surface fluxes. We discuss the important role of electron scattering in determining the EUV spectra of these objects. The differences between DAs and non-DAs with regard to backwarming effect and surface cooling are summarized.In our discussion of very cool non-DA atmospheres we emphasize the importance of the additional energy transport mechanisms convection and conduction which should both be very effective for Teff < 4000K and which lead to a very flat temperature gradient. This small gradient must lead to a rather featureless surface flux.2. Convection Zones. After a survey of the basic numerical results in this field we investigate the question whether convection in white dwarfs has the same basic properties as convection in other stars. We find that contrary to intuitive expectations the Rayleigh number in very cool non-DAs is higher than in the sun (indicating very turbulent convection). The Prandtl number in these objects is 6 to 7 orders of magnitude higher than in the sun.3. Coronae. The basic methods of the calculation of coronae for white dwarfs are very briefly discussed. We present some results for DA and non-DA stars from unpublished work by D.O. Muchmore and the author. It uses revised values for the emissivities. Only non-DA coronae are of practical interest. DA coronae have much lower densities and temperatures. White dwarf coronae do not generate a stellar wind.

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The closest extremely low-mass white dwarf to the Sun

Monthly Notices of the Royal Astronomical Society Letters ◽

10.1093/mnrasl/slaa068 ◽

2020 ◽

Vol 495 (1) ◽

pp. L129-L134 ◽

Cited By ~ 3

Author(s):

Adela Kawka ◽

Jeffrey D Simpson ◽

Stéphane Vennes ◽

Michael S Bessell ◽

Gary S Da Costa ◽

...

Keyword(s):

Mass Transfer ◽

White Dwarf ◽

The Sun ◽

Evolutionary Models ◽

Velocity Amplitude ◽

Common Envelope ◽

Independent Analysis ◽

Type Ia ◽

Supernova Explosions ◽

Low Mass

ABSTRACT We present the orbit and properties of 2MASS J050051.85−093054.9, establishing it as the closest (d ≈ 71 pc) extremely low-mass white dwarf to the Sun. We find that this star is hydrogen rich with $T_\textrm {eff}\approx 10\, 500$ K, log g ≈ 5.9, and, following evolutionary models, has a mass of ≈0.17 M⊙. Independent analysis of radial velocity and Transiting Exoplanet Survey Satellite(TESS) photometric time series reveals an orbital period of ≈9.5 h. Its high velocity amplitude ($K\approx 144~\textrm {km}\, \textrm {s}^{-1}$) produces a measurable Doppler beaming effect in the TESSlight curve with an amplitude of 1 mmag. The unseen companion is most likely a faint white dwarf. J0500−0930 belongs to a class of post-common envelope systems that will most likely merge through unstable mass transfer and in specific circumstances lead to Type Ia supernova explosions.

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The white dwarf population within 40 pc of the Sun

Astronomy and Astrophysics ◽

10.1051/0004-6361/201528059 ◽

2016 ◽

Vol 588 ◽

pp. A35 ◽

Cited By ~ 11

Author(s):

Santiago Torres ◽

Enrique García-Berro

Keyword(s):

White Dwarf ◽

The Sun

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