Radial Velocity Studies of Close Binary Stars. VIII.

Ruciński, S. M.; Capobianco, Christopher C.; Lu, Wenxian; DeBond, Heide; Thomson, James Robertson; Mochnacki, S. W.; Blake, R. M.; Ogłoza, W.; Stachowski, G.; Rogoziecki, P.

doi:10.1086/374949

Cited by 75 publications

(77 citation statements)

References 15 publications

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“…Finally, we note that if the light center velocities are applied without corrections, both semiamplitudes become 1.1 km s −1 smaller than listed in Table 7, and the derived masses become about 0.03 M lower. Our results differ slightly from those by Rucinski et al (2003), K p = 160.11 ± 0.74 km s −1 , K s = 147.21 ± 0.63 km s −1 , and γ = −12.74 ± 0.46 km s −1 , and are more accurate.…”

Section: Spectroscopic Elementscontrasting

confidence: 99%

Absolute dimensions of eclipsing binaries

Clausen¹,

Olsen²,

Helt³

et al. 2010

A&A

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Context. Double-lined, detached eclipsing binaries are our main source for accurate stellar masses and radii. This paper is the first in a series with focus on the upper half of the main-sequence band and tests of 1-2 M evolutionary models. Aims. We aim to determine absolute dimensions and abundances for the detached eclipsing binary V1130 Tau, and to perform a detailed comparison with results from recent stellar evolutionary models. Methods. uvby light curves and uvbyβ standard photometry have been obtained with the Strömgren Automatic Telescope, and high-resolution spectra have been acquired at the FEROS spectrograph; both are ESO, La Silla facilities. We have applied the Wilson-Devinney model for the photometric analysis, spectroscopic elements are based on radial velocities measured via broadening functions, and [Fe/H] abundances have been determined from synthetic spectra and uvby calibrations. Results. V1130 Tau is a bright (m V = 6.56), nearby (71 ± 2 pc) detached system with a circular orbit (P = 0. d 80). The components are deformed with filling factors above 0.9. Their masses and radii have been established to 0.6-0.7%. We derive a [Fe/H] abundance of −0.25 ± 0.10. The measured rotational velocities, 92.4 ± 1.1 (primary) and 104.7 ± 2.7 (secondary) km s −1 , are in fair agreement with synchronization. The larger 1.39 M secondary component has evolved to the middle of the main-sequence band and is slightly cooler than the 1.31 M primary. Yonsai-Yale, BaSTI, and Granada evolutionary models for the observed metal abundance and a "normal" He content of Y = 0.25−0.26, marginally reproduce the components at ages between 1.8 and 2.1 Gyr. All such models are, however, systematically about 200 K hotter than observed and predict ages for the more massive component, which are systematically higher than for the less massive component. These trends can not be removed by adjusting the amount of core overshoot or envelope convection level, or by including rotation in the model calculations. They may be due to proximity effects in V1130 Tau, but on the other hand, we find excellent agreement for 2.5-2.8 Gyr Granada models with a slightly lower Y of 0.23-0.24. Conclusions. V1130 Tau is a valuable addition to the very few well-studied 1-2 M binaries with component(s) in the upper half of the main-sequence band, or beyond. The stars are not evolved enough to provide new information on the dependence of core overshoot on mass (and abundance), but might -together with a larger sample of well-detached systems -be useful for further tuning of the helium enrichment law. Analyses of such systems are in progress.

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Section: Spectroscopic Elementscontrasting

confidence: 99%

Absolute dimensions of eclipsing binaries

Clausen¹,

Olsen²,

Helt³

et al. 2010

A&A

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“…The results reveal that V410 Aur is an A-type contact binary with a deep degree of overcontact of 52:4% AE 6:2%. The photometric mass ratio of q sp ¼ 0:1428 AE 0:0026 agrees well with the spectroscopic mass ratio of q sp ¼ 0:144AE 0:013 ( Rucinski et al 2003). When reanalyzing the photometric solution for XY Boo, a total of 441 observations in the V band and 440 observations in the B band (Binnendijk 1971) were used.…”

Section: Photometric Solutionssupporting

confidence: 66%

“…Using spectroscopic elements for V410 Aur ( Rucinski et al 2003) and XY Boo ( McLean & Hilditch 1983), we (re)determined the absolute physical parameters for those two binaries and listed them in Table 9. Unfortunately, there exist much larger errors in the derivation of the absolute parameters for XY Boo due to much larger errors in the radial velocity amplitudes of K 1 and K 2 , which are up to 28.2% and 23.7%, respectively.…”

Section: The Absolute Parameters and The Mass Transfer Ratementioning

confidence: 99%

“…With Rucinski's simplified light-curve synthesis method, the preliminary orbital analysis of the Hipparcos photometric observations was performed by Selam (2004), who gave the geometric elements of this system. Rucinski et al (2003) were the first to publish radial velocity observations of the binary and those of the third component. The spectroscopically observed epoch of the primary eclipse is HJD 2,452,061.1068.…”

Section: Introductionmentioning

confidence: 99%

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Deep, Low Mass Ratio Overcontact Binary Systems. IV. V410 Aurigae and XY Bootis

2005

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The complete charge-coupled device (CCD) light curves in the V, R, and I bands for the eclipsing binary V410 Aur were observed at the Yunnan Observatory in China. Four new light minimum times of V410 Aur were derived from new observations. The photometric solution for V410 Aur was obtained for the first time, while the orbital elements for XY Boo (observed by Binnendijk in 1971) were reanalyzed by using the latest Wilson-Devinney code. The third light contributions to the total lights of the two binaries are obtained. The results reveal that both systems are A-subtype W UMa binaries with low mass ratios and deep degrees of overcontact (i.e., q ph ¼ 0:1428 and f ¼ 52:4% for V410 Aur, and q ph ¼ 0:1855 and f ¼ 55:9% for XY Boo). The photometric mass ratios of the two binaries are very consistent with the spectroscopic mass ratios. By combining the spectroscopic elements with our photometric solutions, the absolute photometric parameters for V410 Aur and XY Boo are (re)determined. Analyzing the orbital periods of the two binaries, it is discovered that their orbital periods show continuous period increases, suggesting that the systems are undergoing mass transfer from the less massive component to the more massive one through the inner Lagrangian point L 1 . This kind of binary, with a low mass ratio, a deep degree of overcontact, and a continuous period increase, may coalesce into a rapidly rotating single star due to tidal instability.

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“…Pantazis & Niarchos (1998) empirically determined the gravity darkening coefficient for V523 Cas to be 0:53 AE 0:02, which is very different from the theoretical value of 0.32 (Lucy 1967) for convective atmospheres. Further modeling and the publication of new, high-precision radial velocity curves by Rucinski et al (2003) have shown that this departure was not needed, as we show with the simultaneous solution presented in this paper.…”

Section: Introductionmentioning

confidence: 57%

The Physical Nature and Orbital Behavior of V523 Cassiopeiae

Samec

Faulkner

Williams³

2004

Astron J

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V523 Cassiopeiae is a dwarf contact binary with one of the shortest orbital periods among the nondegenerate systems. Its orbital history is marked by large period changes. The photometrically determined mass ratios have historically been inconsistent with those calculated from radial velocity curves. In 1998 we acquired highprecision and standardized Johnson-Cousins UBV light curves. Our simultaneous BV light curve/radial velocity curve solutions provided good fits to both the light curves and the radial velocity curves using standard gravity darkening coefficients with a mass ratio of $0.5. Seven precision mean epochs of minimum light were determined from these observations. We combine these with all available published times of minimum light, along with 50 times of low light found from a search of the archival Harvard plate stacks in the interval 1901-1942 to give us 567 eclipse timings. Our period study covers nearly 160,000 orbits, or $102 yr. We find a high-amplitude sinusoidal variation with a period of 101 AE 7 yr, overlaid on a strong continuous period increase. The quadratic term is common in contact binaries, but a sinusoidal one is not. This suggests a hierarchical three-star system. Assuming that this is the case and that the inclination from our orbital solution for the close pair is the same as the larger orbit, we obtain a mass for the third star of 0.41 M . This is similar to the masses of the stars that comprise the contact binary. If this scenario is correct, V523 Cas consists of a trio of late K and early M-type dwarfs having a total mass of $1.6 M . We show that high-resolution imaging can confirm this suggestion.

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Radial Velocity Studies of Close Binary Stars. VIII.

Cited by 75 publications

References 15 publications

Absolute dimensions of eclipsing binaries

Absolute dimensions of eclipsing binaries

Deep, Low Mass Ratio Overcontact Binary Systems. IV. V410 Aurigae and XY Bootis

The Physical Nature and Orbital Behavior of V523 Cassiopeiae

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