Preliminary orbital elements of six visual binary stars

Scardia, M.; Prieur, Jean‐Louis; Pansecchi, Luigi; Argyle, R. W.

doi:10.1002/asna.200710966

Cited by 28 publications

(50 citation statements)

References 12 publications

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“…For instance, Evans et al (2006) set an upper limit of ∼20 mas using the Hubble Space Telescope in the farultraviolet (although depending on the brightness of the stars). Scardia et al (2008) mentioned the detection of the companion from speckle interferometry in the V band, and measured a separation of 160 mas, while most of previous speckle observations failed to resolve the system (from 1976(from to 2005(from , see e.g. McAlister 1978Hartkopf & McAlister 1984;Evans et al 2006, see the last reference for a more detailled discussion), setting a separation <35 mas.…”

Section: V1334 Cygmentioning

confidence: 99%

Multiplicity of Galactic Cepheids from long-baseline interferometry

Gallenne¹,

Monnier²,

Mérand³

et al. 2013

A&A

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Context. More than 60% of Cepheids are in binary or multiple systems. Studying such systems could lead to a better understanding of the age and evolution of Cepheids. These are also useful tools to estimate the mass of Cepheids, and constrain theoretical models of their pulsation and evolution. Aims. We aim at determining the masses of Cepheids in binary systems, as well as their geometric distances and the flux contribution of the companions. The combination of interferometry with spectroscopy will offer a unique and independent estimate of the Cepheid masses. Methods. Using long-baseline interferometry at visible and infrared wavelengths, it is possible to spatially resolve binary systems containing a Cepheid down to milliarcsecond separations. Based on the resulting visual orbit and radial velocities, we can then derive the fundamental parameters of these systems, particularly the masses of the components and the geometric distance. We therefore performed interferometric observations of the first-overtone mode Cepheid V1334 Cyg with the CHARA/MIRC combiner. Results. We report the first detection of a Cepheid companion using long-baseline interferometry. We detect the signature of a companion orbiting V1334 Cyg at two epochs. We measure a flux ratio between the companion and the Cepheid f = 3.10 ± 0.08%, giving an apparent magnitude m H = 8.47 ± 0.15 mag. The combination of interferometric and spectroscopic data have enabled the unique determination of the orbital elements. P = 1938.6 ± 1.2 days, T p = 2 443 616.1 ± 7.3, a = 8.54 ± 0.51 mas, i = 124.7 ± 1.8• , e = 0.190 ± 0.013, ω = 228.7 ± 1.6• , and Ω = 206.3 ± 9.4• . We derive a minimal distance d ∼ 691 pc, a minimum mass for both stars of 3.6 M , with a spectral type earlier than B5.5V for the companion star. Our measured flux ratio suggests that radial velocity detection of the companion using spectroscopy is within reach, and would provide an orbital parallax and model-free masses.

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Section: V1334 Cygmentioning

confidence: 99%

Multiplicity of Galactic Cepheids from long-baseline interferometry

Gallenne¹,

Monnier²,

Mérand³

et al. 2013

A&A

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“…A.8) improves the spectroscopic orbital elements provided by Abt & Willmarth (2006) for that system. AC 15 AB is a triple system, with the separation Aa-Ab amounting to 0.228 and that of AB to 0.851 in 2005, according to Scardia et al (2008). WDS 18428+5938AB.…”

Section: Geometrical Elements System Coordinates Parallaxmentioning

confidence: 99%

Are the orbital poles of binary stars in the solar neighbourhood anisotropically distributed?

Agati

Bonneau

Jorissen

et al. 2015

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We test whether or not the orbital poles of the systems in the solar neighbourhood are isotropically distributed on the celestial sphere. The problem is plagued by the ambiguity on the position of the ascending node. Of the 95 systems closer than 18 pc from the Sun with an orbit in the 6th Catalogue of Orbits of Visual Binaries, the pole ambiguity could be resolved for 51 systems using radial velocity collected in the literature and CORAVEL database or acquired with the HERMES/Mercator spectrograph. For several systems, we can correct the erroneous nodes in the 6th Catalogue of Orbits and obtain new combined spectroscopic/astrometric orbits for seven systems [WDS 01083+5455Aa,Ab; 01418+4237AB; 02278+0426AB (SB2); 09006+4147AB (SB2); 16413+3136AB; 17121+4540AB; 18070+3034AB]. We used of spherical statistics to test for possible anisotropy. After ordering the binary systems by increasing distance from the Sun, we computed the false-alarm probability for subsamples of increasing sizes, from N = 1 up to the full sample of 51 systems. Rayleigh-Watson and Beran tests deliver a false-alarm probability of 0.5% for the 20 systems closer than 8.1 pc. To evaluate the robustness of this conclusion, we used a jackknife approach, for which we repeated this procedure after removing one system at a time from the full sample. The false-alarm probability was then found to vary between 1.5% and 0.1%, depending on which system is removed. The reality of the deviation from isotropy can thus not be assessed with certainty at this stage, because only so few systems are available, despite our efforts to increase the sample. However, when considering the full sample of 51 systems, the concentration of poles toward the Galactic position l = 46.0• , b = 37• , as observed in the 8.1 pc sphere, totally vanishes (the Rayleigh-Watson false-alarm probability then rises to 18%).

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“…comm.). This binary system has been observed from 1975 until today (Heintz 1975;Scardia et al 2008). Unfortunately given the separation angles measured, the orbital period is likely to be longer than 600 years which makes the determination of the orbit rather unlikely in the near term.…”

Section: Introductionmentioning

confidence: 99%

A seismic and gravitationally bound double star observed byKepler

Appourchaux

Antia

Ball

et al. 2015

A&A

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Context. Solar-like oscillations have been observed by Kepler and CoRoT in many solar-type stars, thereby providing a way to probe stars using asteroseismology. Aims. The derivation of stellar parameters has usually been done with single stars. The aim of the paper is to derive the stellar parameters of a double-star system (HIP 93511), for which an interferometric orbit has been observed along with asteroseismic measurements. Methods. We used a time series of nearly two years of data for the double star to detect the two oscillation-mode envelopes that appear in the power spectrum. Using a new scaling relation based on luminosity, we derived the radius and mass of each star. We derived the age of each star using two proxies: one based upon the large frequency separation and a new one based upon the small frequency separation. Using stellar modelling, the mode frequencies allowed us to derive the radius, the mass, and the age of each component. In addition, speckle interferometry performed since 2006 has enabled us to recover the orbit of the system and the total mass of the system. Results. From the determination of the orbit, the total mass of the system is 2.34 +0.45 −0.33 M . The total seismic mass using scaling relations is 2.47 ± 0.07 M . The seismic age derived using the new proxy based upon the small frequency separation is 3.5 ± 0.3 Gyr. Based on stellar modelling, the mean common age of the system is 2.7-3.9 Gyr. The mean total seismic mass of the system is 2.34-2.53 M consistent with what we determined independently with the orbit. The stellar models provide the mean radius, mass, and age of the stars as R A = 1.82−1.87 R , M A = 1.25−1.39 M , Age A = 2.6-3.5 Gyr; R B = 1.22−1.25 R , M B = 1.08−1.14 M , Age B = 3.35-4.21 Gyr. The models provide two sets of values for Star A: [1.25-1.27] M and [1.34-1.39] M . We detect a convective core in Star A, while Star B does not have any. For the metallicity of the binary system of Z ≈ 0.02, we set the limit between stars having a convective core in the range [1.14-1.25] M .

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Preliminary orbital elements of six visual binary stars

Cited by 28 publications

References 12 publications

Multiplicity of Galactic Cepheids from long-baseline interferometry

Multiplicity of Galactic Cepheids from long-baseline interferometry

Are the orbital poles of binary stars in the solar neighbourhood anisotropically distributed?

A seismic and gravitationally bound double star observed byKepler

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