scholarly journals Masses and other parameters of massive binaries

2003 ◽  
Vol 212 ◽  
pp. 91-100 ◽  
Author(s):  
Douglas R. Gies
Keyword(s):  
Binary Stars ◽  
Temperature Scale ◽  
Stellar Mass ◽  
Spectroscopic Binaries ◽  
Lower Temperature ◽  
The Masses ◽  
Good Agreement

Binary stars provide us with the means to measure stellar mass. Here I present several lists of known O-type stars with reliable mass estimates that are members of eclipsing, double-lined spectroscopic binaries. The masses of young, unevolved stars in binaries are suitable for testing the predictions of evolutionary codes, and there is good agreement between the observed and predicted masses (based upon temperature and luminosity) if the lower temperature scale from line-blanketed model atmospheres is adopted. A final table lists masses for systems in a wide variety of advanced evolutionary stages.

scholarly journals On the Distribution of Young Spectroscopic Binary Stars Over the Major Semiaxes of their Orbits

1982 ◽  
Vol 69 ◽  
pp. 129-131
Author(s):  
E.I. Popova ◽  
A.V. Tutukov ◽  
B.M. Shustov ◽  
L.R. Yungelson
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Spectroscopic Binaries ◽  
Close Binary ◽  
Physical Parameters ◽  
Origin And Evolution ◽  
Spectroscopic Binary ◽  
Visible Spectra ◽  
Major Semiaxes ◽  
The Masses

About 60% of stars of the disc population in our Galaxy are close binary systems (CBS). Half of the known CBS are spectroscopic binary stars (Kraitcheva et al., 1978).To know the distribution of a correlation between the masses of CBS components and semiaxes of their orbits is necessary for the investigation of the origin and evolution of CBS. For such statistical investigations, a catalogue of CBS was compiled at the Astronomical Council. The catalogue is based on the 6th Batten catalogue (Batten, 1967), its extensions (Pedoussant and Ginestet, 1971; Pedoussant and Carquillat, 1973) and data published up to the end of 1980 (Popova et al., 1981). Now it is recorded on magnetic tape and contains data on 1041 spectroscopic binaries; 333 of them are stars with two visible spectra. The latter are mostly systems prior to mass exchange and the distribution of physical parameters in these systems reflects the distribution and presumably conditions at the time of formation. Using some assumptions, we can obtain for spectroscopic binaries masses of the components M1 and M2 (or the ratio q = M1/M2) and semiaxes of their orbits. Masses of components with the known sin i were obtained by the usual technique; when sin i was not known, masses were estimated from the spectra. We shall discuss here the distribution of CBS in the M-a plane.

scholarly journals Masses of the components of SB2 binaries observed with Gaia – V. Accurate SB2 orbits for 10 binaries and masses of the components of 5 binaries

2020 ◽  
Vol 496 (2) ◽  
pp. 1355-1368
Author(s):  
J-L Halbwachs ◽  
F Kiefer ◽  
Y Lebreton ◽  
H M J Boffin ◽  
F Arenou ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Binary Stars ◽  
Main Sequence ◽  
Spectroscopic Binaries ◽  
Orbital Elements ◽  
Evolved Stars ◽  
The Individual ◽  
The Masses ◽  
Stellar Masses ◽  
Selection Of

ABSTRACT Double-lined spectroscopic binaries (SB2s) are one of the main sources of stellar masses, as additional observations are only needed to give the inclinations of the orbital planes in order to obtain the individual masses of the components. For this reason, we are observing a selection of SB2s using the SOPHIE spectrograph at the Haute-Provence observatory in order to precisely determine their orbital elements. Our objective is to finally obtain masses with an accuracy of the order of one per cent by combining our radial velocity (RV) measurements and the astrometric measurements that will come from the Gaia satellite. We present here the RVs and the re-determined orbits of 10 SB2s. In order to verify the masses, we will derive from Gaia, we obtained interferometric measurements of the ESO VLTI for one of these SB2s. Adding the interferometric or speckle measurements already published by us or by others for four other stars, we finally obtain the masses of the components of five binary stars, with masses ranging from 0.51 to 2.2 solar masses, including main-sequence dwarfs and some more evolved stars whose location in the HR diagram has been estimated.

A study of the physical properties of SB2s with both the visual and spectroscopic orbits

2020 ◽  
Vol 492 (2) ◽  
pp. 2709-2721
Author(s):  
Luca Piccotti ◽  
José Ángel Docobo ◽  
Roberta Carini ◽  
Vakhtang S Tamazian ◽  
Enzo Brocato ◽  
...  
Keyword(s):  
Stellar Model ◽  
Spectroscopic Binaries ◽  
Adopted Model ◽  
Magnitude Diagram ◽  
Trigonometric Parallaxes ◽  
The One ◽  
The Masses ◽  
Almost All ◽  
Unique Mass ◽  
Good Agreement

ABSTRACT The study of a selected set of 69 double-lined spectroscopic binaries (SB2) with well-defined visual and spectroscopic orbits was carried out. The orbital parallax, the mass, the colour, and the luminosity of each component were derived from observational data for almost all of these systems. We have also obtained an independent estimation of the component masses by comparing the colour–magnitude diagram (CMD) to the stellar evolution tracks reported by Pietrinferni. Nearly all of the observational points on the CMD are located between two tracks of slightly different mass or which fall very close to the one corresponding to a unique mass value. The masses obtained from the stellar model are in good agreement with their empirical values determined by parallax techniques (orbital, Gaia, and dynamical). This means that our adopted model is rather reliable and can therefore be used to infer further information, such as the age of each component in the studied systems. Our results indicate a fair correspondence between the age of primaries and secondary stars within 3σ. Nevertheless, we caution that these age indications suffer of uncertainties due to both inhomogeneities/low precision of the adopted photometric data and possible systematics. Finally, it is statistically shown that along with the orbital and trigonometric parallaxes, the dynamical parallax can serve as a reliable tool for distance estimates.

scholarly journals Significant uncertainties from calibrating overshooting with eclipsing binary systems

2018 ◽  
Vol 618 ◽  
pp. A177 ◽  
Author(s):  
Thomas Constantino ◽  
Isabelle Baraffe
Keyword(s):  
Stellar Evolution ◽  
Binary Stars ◽  
Binary Systems ◽  
Precise Measurement ◽  
Main Sequence ◽  
Stellar Mass ◽  
Main Sequence Stars ◽  
Eclipsing Binary ◽  
The Masses ◽  
Convective Boundaries

The precise measurement of the masses and radii of stars in eclipsing binary systems provides a window into uncertain processes in stellar evolution, especially mixing at convective boundaries. Recently, these data have been used to calibrate models of convective overshooting in the cores of main sequence stars. In this study we have used a small representative sample of eclipsing binary stars with 1.25 ≤ M/M⊙ < 4.2 to test how precisely this method can constrain the overshooting and whether the data support a universal stellar mass–overshooting relation. We do not recover the previously reported stellar mass dependence for the extent of overshooting and in each case we find there is a substantial amount of uncertainty, that is, the same binary pair can be matched by models with different amounts of overshooting. Models with a moderate overshooting parameter 0.013 ≤ fos ≤ 0.014 (using the scheme from Herwig et al. 1997, A&A, 324, L81) are consistent with all eight systems studied. Generally, a much larger range of f is suitable for individual systems. In the case of main sequence and early post-main sequence stars, large changes in the amount of overshooting have little effect on the radius and effective temperature, and therefore the method is of extremely limited utility.

scholarly journals The Potential of Long–Baseline Optical Interferometry of Binary Stars

1992 ◽  
Vol 135 ◽  
pp. 527-535 ◽  
Author(s):  
H.A. McAlister
Keyword(s):  
Binary Stars ◽  
Speckle Interferometry ◽  
Stellar Mass ◽  
Optical Interferometry ◽  
Spectroscopic Binaries ◽  
Direct Imaging ◽  
Multiple Star ◽  
Long Baseline ◽  
Stellar Interferometer

AbstractInterferometric arrays possessing sub-milliarcsecond resolution are either about to be fully scientifically productive, as in the case of the Sydney University Stellar Interferometer, or are under various stages of planning and development. The 1990’s will thus witness a hundred–fold gain in resolution over speckle interferometry at the largest telescopes and 5,000 times the resolution of classical direct imaging. Where speckle interferometry can now resolve binary stars with periods of 1 to 2 years, interferometric arrays with baselines of hundreds of meters will resolve binaries with periods of a few hours. Arrays will resolve the majority of the known spectroscopic binaries, providing a substantial increase in the quantity and quality of stellar mass determinations. Surveys for new binaries among the field stars and other restricted samples will be accomplished with unprecedented completeness. The remarkable enhancement in resolution we are about to witness from facilities like SUSI and our own proposed CHARA Array will quite literally revolutionize the field of double and multiple star research.

scholarly journals Physical Parameters and Chemical Composition of Components of the Am-Type Binary System RR Lyncis

1993 ◽  
Vol 138 ◽  
pp. 192-196
Author(s):  
L.S. Lyubimkov ◽  
T.M. Rachkovskaya
Keyword(s):  
Chemical Composition ◽  
Binary System ◽  
Binary Stars ◽  
Spectroscopic Binaries ◽  
Theoretical Modelling ◽  
Physical Parameters ◽  
Accurate Data ◽  
Element Abundances ◽  
Widespread Phenomenon ◽  
Chemical Anomalies

Duplicity is a very widespread phenomenon among Am-stars. For instance, Abt (1961) investigating 25 such stars found out that 22 of them are spectroscopic binaries. However this important phenomenon is ignored usually in chemical composition investigations of Am-stars. Consequently some “mean” element abundances are determined, which can noticeably differ from real abundances in atmospheres of components. Moreover false chemical anomalies can appear, as shown by the theoretical modelling of spectra of binary stars (Lyubimkov, 1989, 1992). Meanwhile accurate data on chemical composition of Am-stars must be considered as observational test for any hypothesis suggested for explanation of these objects.

Isotopic Thermal Diffusion Factors for Helium and Neon at Low Temperatures

1963 ◽  
Vol 18 (2) ◽  
pp. 242-245 ◽  
Author(s):  
W. W. Watson ◽  
A. J. Howard ◽  
N. E. Miller ◽  
R. M. Shiffrin
Keyword(s):  
Thermal Diffusion ◽  
Low Temperatures ◽  
Quantum Corrections ◽  
Intermolecular Potential ◽  
De Vries ◽  
Lower Temperature ◽  
Improved Accuracy ◽  
Good Agreement

With an all-metal “swing separator” having unique features, thermal diffusion factors αT for He3/He4 and Ne20Ne22 have been measured with improved accuracy down to average gas temperatures T̅=136°K. For helium αT is 0.0696 ± 0.0010 at 136°K, dropping gradually to 0.0651 ±0.0010 at 313°K. These data, plus measurements by Van der Valk and de Vries at somewhat higher temperatures, agree best with values predicted by an exp-six intermolecular potential with ε/k=9.16 and α=12.7. We are extending these helium measurements down to T=4°K for the lower temperature, to detect if possible quantum corrections to the intermolecular potential. For neon αT increases from 0.0166 ± 0.0010 at 136°K to 0.0233 ± 0.0020 at 310°K, considerably higher than our previously reported values. These T. D. factors for neon are in good agreement with values calculated from an exp-six potential with ε/k = 46.0 ± 0.6 and α=13.

scholarly journals Hadronic vacuum polarization and vector-meson resonance parameters from $$\varvec{e^+e^-\rightarrow \pi ^0\gamma }$$

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Bai-Long Hoid ◽  
Martin Hoferichter ◽  
Bastian Kubis
Keyword(s):  
Transition Form Factor ◽  
Vacuum Polarization ◽  
Transition Form ◽  
Isospin Breaking ◽  
Meson Resonance ◽  
Resonance Parameters ◽  
Polarization Correction ◽  
Dispersive Representation ◽  
The Masses ◽  
Good Agreement

AbstractWe study the reaction $$e^+e^-\rightarrow \pi ^0\gamma $$ e + e - → π 0 γ based on a dispersive representation of the underlying $$\pi ^0\rightarrow \gamma \gamma ^*$$ π 0 → γ γ ∗ transition form factor. As a first application, we evaluate the contribution of the $$\pi ^0\gamma $$ π 0 γ channel to the hadronic-vacuum-polarization correction to the anomalous magnetic moment of the muon. We find $$a_\mu ^{\pi ^0\gamma }\big |_{\le 1.35\,\text {GeV}}=43.8(6)\times 10^{-11}$$ a μ π 0 γ | ≤ 1.35 GeV = 43.8 ( 6 ) × 10 - 11 , in line with evaluations from the direct integration of the data. Second, our fit determines the resonance parameters of $$\omega $$ ω and $$\phi $$ ϕ . We observe good agreement with the $$e^+e^-\rightarrow 3\pi $$ e + e - → 3 π channel, explaining a previous tension in the $$\omega $$ ω mass between $$\pi ^0\gamma $$ π 0 γ and $$3\pi $$ 3 π by an unphysical phase in the fit function. Combining both channels we find $${\bar{M}}_\omega =782.736(24)\,\text {MeV}$$ M ¯ ω = 782.736 ( 24 ) MeV and $${\bar{M}}_\phi =1019.457(20)\,\text {MeV}$$ M ¯ ϕ = 1019.457 ( 20 ) MeV for the masses including vacuum-polarization corrections. The $$\phi $$ ϕ mass agrees perfectly with the PDG average, which is dominated by determinations from the $${\bar{K}} K$$ K ¯ K channel, demonstrating consistency with $$3\pi $$ 3 π and $$\pi ^0\gamma $$ π 0 γ . For the $$\omega $$ ω mass, our result is consistent but more precise, exacerbating tensions with the $$\omega $$ ω mass extracted via isospin-breaking effects from the $$2\pi $$ 2 π channel.

Sign in / Sign up

Export Citation Format

Share Document