Radial Velocities

Andersen, J.; Latham, D. W.; Florsch, A.; Maurice, E.; Mayor, M.; McClure, R. D.; Philip, A. G. D.

doi:10.1007/978-94-009-2981-4_22

Cited by 15 publications

(25 citation statements)

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“…A lower amplitude of He II absorption radial velocity variations probably arises because despite the possible line-blending effects, these lines are also blended with those of the third star in the system. As noted by Andersen (1975) for the diffuse He I lines, pair-blending effects are appreciable on lines which show extensive wings, even if their cores appear well defined and resolved. This effect probably also affects the He II absorptions.…”

Section: The Radial Velocity Orbitmentioning

confidence: 73%

The nearest star of spectral type O3: a component of the multiple system HD 150136

Niemelä

Gamen

2005

Monthly Notices of the Royal Astronomical Society

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From radial velocities determined in high signal‐to‐noise digital spectra, we report the discovery that the brightest component of the binary system HD 150136 is of spectral type O3. We also present the first double‐lined orbital solution for this binary. Our radial velocities confirm the previously published spectroscopic orbital period of 2.6 d. He ii absorptions appear double at quadratures, but single lines of N v and N iv visible in our spectra define a radial velocity orbit of higher semi‐amplitude for the primary component than do the He ii lines. From our orbital analysis, we obtain minimum masses for the binary components of 27 and 18 M⊙. The neutral He absorptions apparently do not follow the orbital motion of any of the binary components, thus they most probably arise in a third star in the system.

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Section: The Radial Velocity Orbitmentioning

confidence: 73%

The nearest star of spectral type O3: a component of the multiple system HD 150136

Niemelä

Gamen

2005

Monthly Notices of the Royal Astronomical Society

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“…For this reason the best spectra were selected by eye, leaving 16 covering the wavelength region of 4450-4715 Å and six spectra covering 4230-4500 Å. The hydrogen and helium lines at 4340, 4471 and 4686 Å were masked to avoid significant errors due to the blending of broad spectral lines (Andersen 1975). The resulting radial velocities are given in Table 7 and were fitted using SBOP in single-lined Lehman-Filhés mode.…”

Section: S P E C T Ro S C O P I C O R B I T Smentioning

confidence: 99%

Eclipsing binaries in open clusters - II. V453 Cyg in NGC 6871

Southworth

Maxted

Smalley

2004

Monthly Notices of the Royal Astronomical Society

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318

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We derive absolute dimensions of the early B‐type detached eclipsing binary V453 Cygni (B0.4 IV + B0.7 IV, P= 3.89 d), a member of the open cluster NGC 6871. From the analysis of new, high‐resolution spectroscopy and the UBV light curves of Cohen, we find the masses to be 14.36 ± 0.20 and 11.11 ± 0.13 M⊙, the radii to be 8.55 ± 0.06 and 5.49 ± 0.06 R⊙, and the effective temperatures to be 26 600 ± 500 and 25 500 ± 800 K for the primary and secondary stars, respectively. The surface gravity values of log g= 3.731 ± 0.012 and 4.005 ± 0.015 indicate that V453 Cyg is reaching the end of its main‐sequence lifetime. We have determined the apsidal motion period of the system to be 66.4 ± 1.8 yr using the technique of Lacy extended to include spectroscopic data as well as times of minimum light, giving a density concentration coefficient of log k2=−2.226 ± 0.024. Contaminating (third) light has been detected for the first time in the light curve of V453 Cyg; previous analyses without this effect systematically underestimate the ratio of the radii of the two stars. The absolute dimensions of the system have been compared with the stellar evolution models of the Granada, Geneva, Padova and Cambridge groups. All model sets fit the data on V453 Cyg for solar helium and metal abundances and an age of 10.0 ± 0.2 Myr. The Granada models also agree fully with the observed log k2 once general relativistic effects have been accounted for. The Cambridge models with convective core overshooting fit V453 Cyg better than those without. Given this success of the theoretical predictions, we briefly discuss which eclipsing binaries should be studied in order to challenge the models further.

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“…These are split between two spectral intervals of length 260 Å, reciprocal dispersion 0.11 Å pixel −1 and resolution 0.20 Å. Most spectra are centred on 4360 Å and the remainder on 4580 Å: both data sets cover the He I λ4471 and Mg II λ4481 lines, which are good lines for radialvelocity (RV) determination over a wide range of spectral types (Andersen 1975). A few additional spectra were obtained with central wavelengths of 4340 and 4840 Å; they are not used here.…”

Section: La Palma Spectramentioning

confidence: 99%

Chemical evolution of high-mass stars in close binaries - I. The eclipsing binary V453 Cygni

Pavlovski

Southworth

2009

Monthly Notices of the Royal Astronomical Society

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The eclipsing and double‐lined spectroscopic binary system V453 Cygni consists of two early B‐type stars, one of which is nearing the terminal age main sequence and one which is roughly halfway through its main‐sequence lifetime. Accurate measurements of the masses and radii of the two stars are available, which makes a detailed abundance analysis both more interesting and more precise than for isolated stars. We have reconstructed the spectra of the individual components of V453 Cyg from the observed composite spectra using the technique of spectral disentangling. From these disentangled spectra, we have obtained improved effective temperature measurements of 27 900 ± 400 and 26 200 ± 500 K, for the primary and secondary stars, respectively, by fitting non local thermodynamic equilibrium theoretical line profiles to the hydrogen Balmer lines. Armed with these high‐precision effective temperatures and the accurately known surface gravities of the stars we have obtained the abundances of helium and metallic elements. A detailed abundance analysis of the primary star shows a normal (solar) helium abundance if the microturbulence velocity derived from metallic lines is used. The elemental abundances show no indication that CNO‐processed material is present in the photosphere of this high‐mass terminal age main‐sequence star. The elemental abundances of the secondary star were derived by a differential study against a template spectrum of a star with similar characteristics. Both the primary and secondary components display elemental abundances which are in the ranges observed in the Galactic OB stars.

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Radial Velocities

Cited by 15 publications

References 0 publications

The nearest star of spectral type O3: a component of the multiple system HD 150136

The nearest star of spectral type O3: a component of the multiple system HD 150136

Eclipsing binaries in open clusters - II. V453 Cyg in NGC 6871

Chemical evolution of high-mass stars in close binaries - I. The eclipsing binary V453 Cygni

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