The Influence of an Outflowing Gaseous Stream on the Determination of Masses of Semidetached Binary Systems

AbstractWesterlund 1 is one of the most massive young clusters known in the Local Group, with an age of 3-5 Myr. It contains an assortment of rare evolved massive stars, such as blue, yellow and red supergiants, Wolf-Rayet stars, a luminous blue variable, and a magnetar, as well as 4 massive eclipsing binary systems (Wddeb, Wd13, Wd36, WR77o, see Bonanos 2007). The eclipsing binaries present a rare opportunity to constrain evolutionary models of massive stars, the distance to the cluster and furthermore, to determine a dynamical lower limit for the mass of a magnetar progenitor. Wddeb, being a detached system, is of great interest as it allows determination of the masses of 2 of the most massive unevolved stars in the cluster. We have analyzed spectra of all 4 eclipsing binaries, taken in 2007-2008 with the 6.5 meter Magellan telescope at Las Campanas Observatory, Chile, and present fundamental parameters (masses, radii) for their component stars.

Download Full-text

An overtone Cepheid variable in an LMC eclipsing binary

International Astronomical Union Colloquium ◽

10.1017/s0252921100010964 ◽

2004 ◽

Vol 193 ◽

pp. 372-376 ◽

Cited By ~ 2

Author(s):

D. Lepischak ◽

D.L. Welch

Keyword(s):

Evolutionary History ◽

Binary Systems ◽

Precise Determination ◽

Light Curves ◽

Intermediate Mass ◽

Eclipsing Binary ◽

Spectroscopic Binary ◽

First Time ◽

Absolute Luminosity

AbstractEclipsing binary systems potentially allow the direct and precise determination of the important properties of their component stars. An eclipsing binary containing a Cepheid variable which is also a double-lined spectroscopic binary would allow, for the first time, the direct measurement of the absolute luminosity and mass of the Cepheid. The MACHO Project LMC database contains five systems whose light curves show variations due to both eclipses and pulsation but only one has been clearly identified as an intermediate-mass, Population I object. This object, MACHO 81.8997.87 (= OGLELMC_SC16 119952) is a 2.035-d overtone Cepheid in an 800.4-d binary system with an M-type companion. Here we present the results of the analysis of the light curve of this system, the implications for its evolutionary history and discuss the prospects for future observations.

Download Full-text

Absolute dimensions of the low-mass eclipsing binary system NSVS 10653195

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935516 ◽

2019 ◽

Vol 627 ◽

pp. A153 ◽

Cited By ~ 2

Author(s):

Ramón Iglesias-Marzoa ◽

María J. Arévalo ◽

Mercedes López-Morales ◽

Guillermo Torres ◽

Carlos Lázaro ◽

...

Keyword(s):

Binary Stars ◽

Binary Systems ◽

Eclipsing Binaries ◽

Low Mass Stars ◽

Orbital Inclination ◽

Eclipsing Binary ◽

Solar Metallicity ◽

Low Mass ◽

Stellar Models ◽

The Masses

Context. Low-mass stars in eclipsing binary systems show radii larger and effective temperatures lower than theoretical stellar models predict for isolated stars with the same masses. Eclipsing binaries with low-mass components are hard to find due to their low luminosity. As a consequence, the analysis of the known low-mass eclipsing systems is key to understand this behavior. Aims. We aim to investigate the mass–radius relation for low-mass stars and the cause of the deviation of the observed radii in low-mass detached eclipsing binary stars (LMDEB) from theoretical stellar models. Methods. We developed a physical model of the LMDEB system NSVS 10653195 to accurately measure the masses and radii of the components. We obtained several high-resolution spectra in order to fit a spectroscopic orbit. Standardized absolute photometry was obtained to measure reliable color indices and to measure the mean Teff of the system in out-of-eclipse phases. We observed and analyzed optical VRI and infrared JK band differential light-curves which were fitted using PHOEBE. A Markov chain Monte-Carlo (MCMC) simulation near the solution found provides robust uncertainties for the fitted parameters. Results. NSVS 10653195 is a detached eclipsing binary composed of two similar stars with masses of M1 = 0.6402 ± 0.0052 M⊙ and M2 = 0.6511 ± 0.0052 M⊙ and radii of R1 = 0.687+0.017−0.024 R⊙ and R2 = 0.672+0.018−0.022 R⊙. Spectral types were estimated to be K6V and K7V. These stars rotate in a circular orbit with an orbital inclination of i = 86.22 ± 0.61 degrees and a period of P = 0.5607222(2) d. The distance to the system is estimated to be d = 135.2+7.6−7.9 pc, in excellent agreement with the value from Gaia. If solar metallicity were assumed, the age of the system would be older than log (age) ∼ 8 based on the Mbol–log Teff diagram. Conclusions. NSVS 10653195 is composed of two oversized and active K stars. While their radii is above model predictions their Teff are in better agreement with models.

Download Full-text

Significant uncertainties from calibrating overshooting with eclipsing binary systems

Astronomy and Astrophysics ◽

10.1051/0004-6361/201833568 ◽

2018 ◽

Vol 618 ◽

pp. A177 ◽

Cited By ~ 10

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.

Download Full-text

THE ARAUCARIA PROJECT. DETERMINATION OF THE LARGE MAGELLANIC CLOUD DISTANCE FROM LATE-TYPE ECLIPSING BINARY SYSTEMS. I. OGLE-051019.64-685812.3

The Astrophysical Journal ◽

10.1088/0004-637x/697/1/862 ◽

2009 ◽

Vol 697 (1) ◽

pp. 862-866 ◽

Cited By ~ 67

Author(s):

Grzegorz Pietrzyński ◽

Ian B. Thompson ◽

Dariusz Graczyk ◽

Wolfgang Gieren ◽

Andrzej Udalski ◽

...

Keyword(s):

Binary Systems ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Late Type ◽

Eclipsing Binary

Download Full-text

The Influence of an Outflowing Gaseous Stream on the Determination of Masses of Semidetached Binary Systems

Calibration of Fundamental Stellar Quantities ◽

10.1007/978-94-009-5456-4_29 ◽

1985 ◽

pp. 385-388

Author(s):

D. Chochol ◽

A. Vittone

Keyword(s):

Binary Systems ◽

Gaseous Stream

Download Full-text

Accurate stellar parameters and distance to two evolved eclipsing binary systems, OGLE-BLG-ECL-123903 and OGLE-BLG-ECL-296596, towards the Galactic bulge

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834298 ◽

2019 ◽

Vol 621 ◽

pp. A93 ◽

Cited By ~ 3

Author(s):

K. Suchomska ◽

D. Graczyk ◽

G. Pietrzyński ◽

W. Gieren ◽

J. Ostrowski ◽

...

Keyword(s):

Gravitational Lensing ◽

Surface Brightness ◽

Binary Systems ◽

Near Infrared ◽

Light Curves ◽

Evolutionary Status ◽

Infrared Photometry ◽

Eclipsing Binary ◽

Orbital Parameters ◽

The Masses

Aims. Our aim is to obtain high-accuracy measurements of the physical and orbital parameters of two evolved eclipsing binary systems, and to use these measurements to study their evolutionary status. We also aim to derive the distances to the systems by using a surface brightness–colour relation and compare these distances with the measurements provided by Gaia. Methods. We measured the physical and orbital parameters of both systems based on V-band and I-band photometry from OGLE, near-infrared photometry obtained with the NTT telescope and the instrument SOFI, as well as high-resolution spectra obtained at ESO 3.6m/HARPS and Clay 6.5/MIKE spectrographs. The light curves and radial-velocity curves were analysed with the Wilson–Devinney code. Results. We analysed two double-lined eclipsing binary systems OGLE-BLG-ECL-123903 and OGLE-BLG-ECL-296596 from the Optical Gravitational Lensing Experiment (OGLE) catalogue. Both systems have a configuration of two well-detached giants stars. The masses of the components of OGLE-BLG-ECL-123903 are M1 = 2.045 ± 0.027 and M2 = 2.074 ± 0.023 M⊙ and the radii are R1 = 9.540 ± 0.049 and R2 = 9.052 ± 0.060 R⊙. For OGLE-BLG-ECL-296596, the masses are M1 = 1.093 ± 0.015 and M2 = 1.125 ± 0.014 M⊙, while the radii are R1 = 18.06 ± 0.28 and R2 = 29.80 ± 0.33 R⊙. Evolutionary status was discussed based on the isochrones and evolutionary tracks from PARSEC and MESA codes. The ages of the systems were established to be around 1.3 Gyr for the OGLE-BLG-ECL-123903 and 7.7 Gyr for the OGLE-BLG-ECL-296596. We also determined the distance to both systems. For OGLE-BLG-ECL-123903 this is equal to d = 2.95 ± 0.06 (stat.) ±0.07 (syst.) kpc, while for the OGLE-BLG-ECL-296596 it is d = 5.68 ± 0.07 (stat.) ±0.14 (syst.) kpc. This is the first analysis of its kind for these unique evolved eclipsing binary systems.

Download Full-text

Determination of Stellar Rotational Velocities

Symposium - International Astronomical Union ◽

10.1017/s0074180900078839 ◽

1985 ◽

Vol 111 ◽

pp. 163-184

Author(s):

Arne Slettebak

Keyword(s):

Radial Velocity ◽

Line Profile ◽

Binary Systems ◽

Profile Analysis ◽

Axial Rotation ◽

Line Profile Analysis ◽

Eclipsing Binary ◽

Rotating Star

The three basic methods for measuring axial rotation of stars had been suggested before the beginning of this century. These are (1) Modulation of starlight due to dark or bright areas on a rotating star; (2) Distortions in the radial velocity curves of eclipsing binary systems; and (3) Line profile analysis. Research in each of these areas is reviewed.

Download Full-text

X-ray and UV emission of the ultrashort-period, low-mass eclipsing binary system BX Trianguli

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834116 ◽

2018 ◽

Vol 619 ◽

pp. A138

Author(s):

V. Perdelwitz ◽

S. Czesla ◽

J. Robrade ◽

T. Pribulla ◽

J. H. M. M. Schmitt

Keyword(s):

Binary System ◽

Light Curve ◽

Binary Systems ◽

Uv Light ◽

Close Binary ◽

Eclipsing Binary ◽

X Ray ◽

Uv Emission ◽

Low Mass ◽

Orbital Modulation

Context.Close binary systems provide an excellent tool for determining stellar parameters such as radii and masses with a high degree of precision. Due to the high rotational velocities, most of these systems exhibit strong signs of magnetic activity, postulated to be the underlying reason for radius inflation in many of the components. Aims.We extend the sample of low-mass binary systems with well-known X-ray properties. Methods.We analyze data from a singular XMM-Newton pointing of the close, low-mass eclipsing binary system BX Tri. The UV light curve was modeled with the eclipsing binary modeling tool PHOEBE and data acquired with the EPIC cameras was analyzed to search for hints of orbital modulation. Results.We find clear evidence of orbital modulation in the UV light curve and show that PHOEBE is fully capable of modeling data within this wavelength range. Comparison to a theoretical flux prediction based on PHOENIX models shows that the majority of UV emission is of photospheric origin. While the X-ray light curve does exhibit strong variations, the signal-to-noise ratio of the observation is insufficient for a clear detection of signs of orbital modulation. There is evidence of a Neupert-like correlation between UV and X-ray data.

Download Full-text