Finding binaries from phase modulation of pulsating stars with Kepler: V. Orbital parameters, with eccentricity and mass-ratio distributions of 341 new binaries

ABSTRACT Measuring phase modulation in pulsating stars has proven to be a highly successful way of finding binary systems. The class of pulsating main-sequence A and F variables, known as δ Scuti stars consists of particularly good targets for this, and the Kepler sample of these has been almost fully exploited. However, some Keplerδ Scuti stars have incorrect temperatures in stellar properties catalogues, and were missed in previous analyses. We used an automated pulsation classification algorithm to find 93 new δ Scuti pulsators among tens of thousands of F-type stars, which we then searched for phase modulation attributable to binarity. We discovered 10 new binary systems and calculated their orbital parameters, which we compared with those of binaries previously discovered in the same way. The results suggest that some of the new companions may be white dwarfs.

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Twin stars as tracers of binary evolution in the Kepler era

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab343 ◽

2021 ◽

Author(s):

Sara Bulut ◽

Baris Hoyman ◽

Ahmet Dervisoglu ◽

Orkun Özdarcan ◽

Ömür Cakilrli

Keyword(s):

High Resolution ◽

Internal Structure ◽

Spectroscopic Analysis ◽

Independent Method ◽

Eclipsing Binaries ◽

Physical Parameters ◽

Evolutionary Status ◽

Mass Ratio ◽

Orbital Parameters ◽

Binary Evolution

Abstract We present results of the combined photometric and spectroscopic analysis of four systems, which are eclipsing binaries with a twin–component (mass ratio q ≃ 1). These are exceptional tools to provide information for probing the internal structure of stars. None of the systems were previously recognized as twin binaries. We used a number of high–resolution optical spectra to calculate the radial velocities and later combined them with photometry to derive orbital parameters. Temperatures and metallicities of systems were estimated from high-resolution spectra. For each binary, we obtained a full set of orbital and physical parameters, reaching precision below 3 per cent in masses and radii for whole pairs. By comparing our results with PARSEC and MIST isochrones, we assess the distance, age and evolutionary status of the researched objects. The primary and/or secondary stars of EPIC 216075815 and EPIC 202843107 are one of the cases where asteroseismic parameters of δ Sct and γ Dor pulsators were confirmed by an independent method and rare examples of the twin–eclipsing binaries, therefore the following analyses and results concern the pulsating nature of the components.

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Finding binaries among Kepler pulsating stars from phase modulation of their pulsations

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stu765 ◽

2014 ◽

Vol 441 (3) ◽

pp. 2515-2527 ◽

Cited By ~ 53

Author(s):

S. J. Murphy ◽

T. R. Bedding ◽

H. Shibahashi ◽

D. W. Kurtz ◽

H. Kjeldsen

Keyword(s):

Phase Modulation ◽

Pulsating Stars

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Asteroseismic search for invisible binary companions

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316006244 ◽

2015 ◽

Vol 11 (A29B) ◽

pp. 642-647

Author(s):

Hiromoto Shibahashi ◽

Simon J. Murphy ◽

Donald W. Kurtz

Keyword(s):

Radial Velocity ◽

Frequency Modulation ◽

Binary Systems ◽

Binary Star ◽

Orbital Parameters ◽

Pulsating Stars ◽

Kepler Mission ◽

Orbital Frequency ◽

Long Time ◽

The Fourier Transform

AbstractContinuous and precise space-based photometry has made it possible to measure the orbital frequency modulation of pulsating stars in binary systems with extremely high precision over long time spans. We present the phase modulation (PM) method for finding binaries among pulsating stars. We demonstrate how the orbital elements of a pulsating binary star can be obtained analytically from photometry alone, without spectroscopic radial velocity measurement. Frequency modulation (FM) caused by binary orbital motion also manifests itself in the Fourier transform, as a multiplet with equal spacing of the orbital frequency. The orbital parameters can also be extracted by analysing the amplitudes and phases of the peaks in these multiplets. We derive analytically the theoretical relations between the multiplet properties and the orbital parameters, and present a method for determining these parameters, including the eccentricity and the argument of periapsis. This, too, is achievable with the photometry alone, without spectroscopic radial velocity measurements. We apply these two methods to Kepler mission data and demonstrate that the results are in good agreement with each other. These methods are used to search for invisible binary companions, including planets and invisible massive objects such as neutron stars and stellar-mass black holes.

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A Study of the Orbital and Intrinsic Variability of the Double-Lined Spectroscopic Binary β Centauri

International Astronomical Union Colloquium ◽

10.1017/s025292110001561x ◽

2002 ◽

Vol 185 ◽

pp. 86-87

Author(s):

M. Ausseloos ◽

C. Aerts ◽

K. Uytterhoeven

Keyword(s):

High Resolution ◽

Orbital Motion ◽

High Signal ◽

Mass Ratio ◽

Eccentric Orbit ◽

Intrinsic Variability ◽

Signal To Noise ◽

Orbital Parameters ◽

Spectroscopic Binary ◽

First Time

AbstractWe introduce our observational study of the orbital motion of β Cen. Using 463 high signal-to-noise, high-resolution spectra obtained over a timespan of 12 years it is shown that the radial velocity of β Cen varies with an orbital period of 357.0 days. We derive for the first time the orbital parameters of β Cen and find a very eccentric orbit (e = 0.81) and similar component masses with a mass ratio M1/M2 = 1.02. Both the primary and the secondary exhibit periodic line-profile variations.

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Gravitational burst radiation from pulsars in the Galactic centre and stellar clusters

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1259 ◽

2020 ◽

Vol 495 (1) ◽

pp. 600-613 ◽

Cited By ~ 2

Author(s):

Tom Kimpson ◽

Kinwah Wu ◽

Silvia Zane

Keyword(s):

Gravitational Radiation ◽

Globular Clusters ◽

Radio Signal ◽

Strong Field ◽

Galactic Centre ◽

Stellar Clusters ◽

Mass Ratio ◽

Pulsar Radio ◽

Orbital Parameters ◽

Pulsar Timing

ABSTRACT Pulsars (PSRs) orbiting intermediate or supermassive black holes at the centre of galaxies and globular clusters are known as Extreme Mass Ratio Binaries (EMRBs) and have been identified as precision probes of strong-field GR. For appropriate orbital parameters, some of these systems may also emit gravitational radiation in a ‘burst-like’ pattern. The observation of this burst radiation in conjunction with the electromagnetic radio timing signal would allow for multimessenger astronomy in strong-field gravitational regimes. In this work we investigate gravitational radiation from these PSR-EMRBs, calculating the waveforms and SNRs and explore the influence of this GW on the pulsar radio signal. We find that for typical PSR-EMRBs, gravitational burst radiation should be detectable from both the Galactic centre and the centre of stellar clusters, and that this radiation will not meaningfully affect the pulsar timing signal, allowing PSR-EMRB to remain ‘clean’ test-beds of strong-field GR.

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Two new double-lined spectroscopic binary white dwarfs

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa466 ◽

2020 ◽

Vol 493 (2) ◽

pp. 2805-2816 ◽

Cited By ~ 1

Author(s):

Mukremin Kilic ◽

A Bédard ◽

P Bergeron ◽

Alekzander Kosakowski

Keyword(s):

Radial Velocity ◽

White Dwarf ◽

White Dwarfs ◽

Binary Systems ◽

Mass Ratio ◽

Orbital Parameters ◽

Long Period ◽

Spectroscopic Binary ◽

Velocity Variations ◽

Period System

ABSTRACT We present radial velocity observations of four binary white dwarf candidates identified through their overluminosity. We identify two new double-lined spectroscopic binary systems, WD 0311–649 and WD 1606+422, and constrain their orbital parameters. WD 0311–649 is a 17.7 h period system with a mass ratio of 1.44 ± 0.06 and WD 1606+422 is a 20.1 h period system with a mass ratio of 1.33 ± 0.03. An additional object, WD 1447–190, is a 43 h period single-lined white dwarf binary, whereas WD 1418–088 does not show any significant velocity variations over time-scales ranging from minutes to decades. We present an overview of the 14 overluminous white dwarfs that were identified by Bédard et al., and find the fraction of double- and single-lined systems to be both 31 per cent. However, an additional 31 per cent of these overluminous white dwarfs do not show any significant radial velocity variations. We demonstrate that these must be in long-period binaries that may be resolved by Gaia astrometry. We also discuss the overabundance of single low-mass white dwarfs identified in the SPY survey, and suggest that some of those systems are also likely long-period binary systems of more massive white dwarfs.

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Radial velocities with CORAVEL: results on stellar variability and duplicity

Symposium - International Astronomical Union ◽

10.1017/s0074180900151770 ◽

1986 ◽

Vol 118 ◽

pp. 385-400

Author(s):

G. Burki ◽

M. Mayor

Keyword(s):

Dynamical Evolution ◽

Distribution Functions ◽

Open Clusters ◽

Formation Mechanisms ◽

Radial Velocity Curve ◽

Stellar Radius ◽

Orbital Parameters ◽

Pulsating Stars ◽

Rr Lyrae ◽

The Galaxy

The complete radial velocity curve has been determined with CORAVEL for many pulsating stars of various classes: cepheid stars in the Galaxy and in the Magellanic Clouds, RR Lyrae, δ Scuti and SX Phoenicis stars. These measurements allow the determination of the radius variation and of the surface acceleration of these stars. In addition, the mean stellar radius of many of these stars has been determined by applying the Baade-Wesselink method.Systematic surveys of definite groups of binary or multiple stars are in progress with CORAVEL in order to determine the distribution functions of the orbital parameters. The eccentricity distributions for the binaries in the open clusters Pleiades, Praesepe, Coma Ber and Hyades are presented and their dependence on the physical processes (star formation mechanisms, mass exchange, tidal circularization, dynamical evolution) is briefly discussed.

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Vector speckle grid: instantaneous incoherent speckle grid for high-precision astrometry and photometry in high-contrast imaging

Astronomy and Astrophysics ◽

10.1051/0004-6361/202037957 ◽

2020 ◽

Vol 638 ◽

pp. A118

Author(s):

S. P. Bos

Keyword(s):

Phase Modulation ◽

Short Exposure ◽

Limiting Factor ◽

Atmospheric Conditions ◽

Contrast Imaging ◽

Orbital Parameters ◽

High Contrast Imaging ◽

Photometric Error ◽

Polarization States ◽

Precision Astrometry

Context. Photometric and astrometric monitoring of directly imaged exoplanets will deliver unique insights into their rotational periods, the distribution of cloud structures, weather, and orbital parameters. As the host star is occulted by the coronagraph, a speckle grid (SG) is introduced to serve as astrometric and photometric reference. Speckle grids are implemented as diffractive pupil-plane optics that generate artificial speckles at known location and brightness. Their performance is limited by the underlying speckle halo caused by evolving uncorrected wavefront errors. The speckle halo will interfere with the coherent SGs, affecting their photometric and astrometric precision. Aims. Our aim is to show that by imposing opposite amplitude or phase modulation on the opposite polarization states, a SG can be instantaneously incoherent with the underlying halo, greatly increasing the precision. We refer to these as vector speckle grids (VSGs). Methods. We derive analytically the mechanism by which the incoherency arises and explore the performance gain in idealised simulations under various atmospheric conditions. Results. We show that the VSG is completely incoherent for unpolarized light and that the fundamental limiting factor is the cross-talk between the speckles in the grid. In simulation, we find that for short-exposure images the VSG reaches a ∼0.3–0.8% photometric error and ∼3−10 × 10−3λ/D astrometric error, which is a performance increase of a factor ∼20 and ∼5, respectively. Furthermore, we outline how VSGs could be implemented using liquid-crystal technology to impose the geometric phase on the circular polarization states. Conclusions. The VSG is a promising new method for generating a photometric and astrometric reference SG that has a greatly increased astrometric and photometric precision.

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Binary fraction of O and B-type stars from LAMOST data

Research in Astronomy and Astrophysics ◽

10.1088/1674-4527/21/11/272 ◽

2021 ◽

Vol 21 (11) ◽

pp. 272

Author(s):

Feng Luo ◽

Yong-Heng Zhao ◽

Jiao Li ◽

Yan-Jun Guo ◽

Chao Liu

Keyword(s):

Binary Stars ◽

Cross Correlation ◽

Stellar Populations ◽

Mass Ratio ◽

Stellar Spectra ◽

Ob Stars ◽

Orbital Parameters ◽

Repeated Observations ◽

Kolmogorov Smirnov ◽

Fixed Power

Abstract Binary stars play an important role in the evolution of stellar populations . The intrinsic binary fraction (f bin) of O and B-type (OB) stars in LAMOST DR5 was investigated in this work. We employed a cross-correlation approach to estimate relative radial velocities for each of the stellar spectra. The algorithm described by Sana et al. (2013) was implemented and several simulations were made to assess the performance of the approach. The binary fraction of the OB stars is estimated through comparing the uni-distribution between observations and simulations with the Kolmogorov-Smirnov tests. Simulations show that it is reliable for stars most of whom have six, seven and eight repeated observations. The uncertainty of orbital parameters of binarity becomes larger when observational frequencies decrease. By adopting the fixed power exponents of π = −0.45 and κ = −1 for period and mass ratio distributions, respectively, we obtain that f bin = 0.4 − 0.06 + 0.05 for the samples with more than three observations. When we consider the full samples with at least two observations, the binary fraction turns out to be 0.37 − 0.03 + 0.03 . These two results are consistent with each other in 1σ.

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