Apsidal Motion and Absolute Parameters of 21 Early-type Small Magellanic Cloud Eccentric Eclipsing Binaries

Zasche, P.; Wolf, M.

doi:10.3847/1538-3881/aafc31

Cited by 13 publications

(7 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The second method is to simultaneously fit all the observational data with a code allowing for the argument of periastron to vary by a linear rate of change in time, thus directly handling apsidal motion rate. Such an analysis has been applied using the PHOEBE code (an open-source project, see [17,18]) in [16,19].…”

Section: In An Eclipsing Binarymentioning

confidence: 99%

What apsidal motion reveals about the interior of massive binary stars

Rosu¹

2021

Bull. Soc. Roy. Sc. de Liège

View full text Add to dashboard Cite

Apart from asteroseismology, the most efficient observational technique allowing to probe the internal structure of a star is the determination of the apsidal motion in close eccentric binary systems. This secular precession of the major axis of the binary orbit depends on the tidal interactions between the two stars. The rate of this motion is directly related to the internal structure of the stars, in particular their inner density profile. Based on radial velocity and light curve measurements made over a long timescale, the rate of apsidal motion can be constrained, together with the fundamental parameters of the stars. Comparing the observationally determined parameters to theoretical models of stellar structure and evolution then constrains the internal structure of the stars. This powerful technique has been known for years, but has been seldom applied - we are reviewing its interest and reveal recent results.

show abstract

Section: In An Eclipsing Binarymentioning

confidence: 99%

What apsidal motion reveals about the interior of massive binary stars

Rosu¹

2021

Bull. Soc. Roy. Sc. de Liège

View full text Add to dashboard Cite

show abstract

“…It is worth noting that the light curve taken with the filter centred on the He ii λ 4686 line is in excellent agreement with the best-fit c 2 -band curve, and does not reveal any strange behaviour due to the phase-dependent He ii λ 4686 emission. The light curves of eclipsing binaries are also quite sensitive to apsidal motion and are frequently used to establish the presence of this phenomenon (e.g., Zasche & Wolf 2019). In the case of HD 152 248, the eclipses were discovered and confirmed well after the discovery of the SB2 nature of the system (Mayer et al 1992).…”

Section: Light Curve Analysismentioning

confidence: 99%

“…Interestingly, some previous studies reported evidence of a secular variation of the argument of periastron ω (Sana et al 2001;Nesslinger et al 2006;Mayer et al 2008). These properties make HD 152 248 an ideal target for the study of apsidal motion (Schmitt et al 2016;Rauw et al 2016;Zasche & Wolf 2019). Apsidal motion consists in a slow precession of the line of apsides in an eccentric binary and stems from the non-spherical shape of the gravitational field of stars in close binaries (Schmitt et al 2016, and references therein).…”

Section: Introductionmentioning

confidence: 99%

Apsidal motion in the massive binary HD 152248

Rosu¹,

Rauw²,

Gosset³

et al. 2020

caosp

View full text Add to dashboard Cite

Context. The eccentric massive binary HD 152 248 (also known as V1007 Sco), which hosts two O7.5 III-II(f) stars, is the most emblematic eclipsing O-star binary in the very young and rich open cluster NGC 6231. Its properties render the system an interesting target for studying tidally induced apsidal motion. Aims. Measuring the rate of apsidal motion in such a binary system gives insight into the internal structure and evolutionary state of the stars composing it. Methods. A large set of optical spectra was used to reconstruct the spectra of the individual binary components and establish their radial velocities using a disentangling code. Radial velocities measured over seven decades were used to establish the rate of apsidal motion. We furthermore analysed the reconstructed spectra with the CMFGEN model atmosphere code to determine stellar and wind properties of the system. Optical photometry was analysed with the Nightfall binary star code. A complete photometric and radial velocity model was constructed in PHOEBE 2 to determine robust uncertainties. Results. We find a rate of apsidal motion of (1.843 +0.064 −0.083 ) • yr −1 . The photometric data indicate an orbital inclination of (67.6 +0.2 −0.1 ) • and Roche-lobe filling factors of both stars of about 0.86. Absolute masses of 29.5 +0.5 −0.4 M and mean stellar radii of 15.07 +0.08 −0.12 R are derived for both stars. We infer an observational value for the internal structure constant of both stars of 0.0010 ± 0.0001. Conclusions. Our in-depth analysis of the massive binary HD 152 248 and the redetermination of its fundamental parameters can serve as a basis for the construction of stellar evolution models to determine theoretical rates of apsidal motion to be compared with the observational one. In addition, the system hosts two twin stars, which offers a unique opportunity to obtain direct insight into the internal structure of the stars.A&A proofs: manuscript no. 37285corr the spectral disentangling are combined with data from the literature in Sect. 4 to establish a preliminary value for the observational rate of apsidal motion. The possibility of a triple system is discussed in Appendix D. Photometric data of HD 152 248 are analysed in Sect. 5 by means of the Nightfall binary star code. In Sect. 6 we construct a complete model in PHOEBE 2 that takes photometric and radial velocity (RV) measurements into account. We determine robust uncertainties on the parameters based on this model. The observational internal structure constant k 2 of the stars is determined in Sect. 7. Finally, we discuss the implications of our study and give our conclusions in Sect. 8. Observational data SpectroscopyTo investigate the optical spectrum of HD 152 248, we extracted 48 high-resolution échelle spectra. Of these, 27 were obtained with the Fiber-fed Extended Range Optical Spectrograph (FEROS) mounted on the European Southern Observatory (ESO) 1.5 m or 2.2 m telescopes in La Silla, Chile (Kaufer et al. 1999). The remaining 21 spectra were obtained with the ES-PaDOns spectrogr...

show abstract

“…In our case we have almost 20-year long coverage, which for orbital periods of 4-5 days, can give a very high precision in the determination of the time-related parameters, like period and times of minima. This in turn let us detect and measure the precession of the line of apsides, which is a very common phenomena in massive binary systems (Garcia et al 2014;Pablo et al 2015;Rauw et al 2016;Zasche & Wolf 2019).…”

Section: Apsidal Motionmentioning

confidence: 99%

Toward Early-type Eclipsing Binaries as Extragalactic Milestones. I. Physical Parameters of OGLE-LMC-ECL-22270 and OGLE-LMC-ECL-06782

Taormina

Pietrzyński

Pilecki

et al. 2019

ApJ

View full text Add to dashboard Cite

In this first paper of the series we describe our project to calibrate the distance determination method based on early-type binary systems. The final objective is to measure accurate, geometrical distances to galaxies beyond the Magellanic Clouds with a precision of 2%. We start with the analysis of two early-type systems for which we have collected all the required spectroscopic and photometric data. Apart from catalog publications, these systems have not been studied yet, and it is the first time the modeling of light and radial velocity curves is performed for them. From the analysis we obtained precise physical parameters of the components, including the masses measured with precision of 0.6-1% and radii with precision of 0.4-3%. For one system we determined the (V − K) color and estimated the distance using the bolometric flux scaling method (DM=18.47±0.15 mag), which agrees well with our accurate determination of the distance to the LMC from late-type giants. For the same system we determined the surface brightness of individual stars using our model, and checked that it is consistent with a recent surface brightness -color relation. We compared our results with evolution theory models of massive stars and found they agree in general, however, models with higher overshooting values give more consistent results. The age of the system was estimated to from 11.7 to 13.8 Myr, depending on the model.

show abstract

Apsidal Motion and Absolute Parameters of 21 Early-type Small Magellanic Cloud Eccentric Eclipsing Binaries

Cited by 13 publications

References 37 publications

What apsidal motion reveals about the interior of massive binary stars

What apsidal motion reveals about the interior of massive binary stars

Apsidal motion in the massive binary HD 152248

Toward Early-type Eclipsing Binaries as Extragalactic Milestones. I. Physical Parameters of OGLE-LMC-ECL-22270 and OGLE-LMC-ECL-06782

Contact Info

Product

Resources

About