Β Lyrae Research Articles

Formation of magnetized spatial structures in the Beta Lyrae system. III. Reflection of magnetically controlled matter in circumbinary structures in helium lines, in particular arising from metastable levels

Spatial gaseous structures in the Beta Lyrae system have been studied with the fact of change in the longitudinal component of the donor's magnetic field during the orbital period in mind. The investigation was based primarily on the study of the dynamics of the circumstellar structures surrounding the binary system as a whole. The special emphasis was placed on the study of complex helium lines, in particular those arising from metastable levels. A number of different observable facts from the ultraviolet to the red spectral region were analyzed. The configuration of the donor magnetic field is a factor that not only enhances mass transfer and influences the formation of spatial gas structures between stellar components but, to some extent, also affects the outflow of matter and the formation of external gas structures around this interacting binary system. Together with previous articles \citep{Skulskyy2020a, Skulskyy2020b}, the pieces of evidence of this work, confirming the reflection of magnetically controlled matter in circumbinary structures, define the basis for a coherent picture of the mass exchange between components and outflows of matter outwards

Formation of magnetized spatial structures in the Beta Lyrae system. II. Reflection of magnetically controlled structures in the visible spectrum

This article proposes a picture of magnetized accretion structures formed during the mass transfer in the Beta Lyrae system. It is shown that the structure of the gaseous flows between the donor and the gainer is due to the spatial configuration of the donor magnetic field. Its dipole axis is deviated substantially from the line joining the centers of the components and is inclined to the orbital plane of the binary system; the center of the magnetic dipole is displaced from the donor center toward the gainer. The surface around the donor magnetic pole, which is close to the gainer, is a region of an additional matter loss from the donor surface. The effective collision of the magnetized plasma with the accretion disk is enhanced by the fast counter-rotation of this disk, especially in the secondary quadrature phases, in which the high-temperature medium and the system of formed accretion flows are observed. This concept is demonstrated, primarily, in the obvious correlations between the phase variability of the donor magnetic field and the corresponding variability of the dynamic and energy characteristics of the various complex lines. This refers to the behavior of the radial velocity curves of the emission-absorption lines formed in the gaseous structures of type H$\alpha$, HeI $\lambda$ 7065, or the variability of their equivalent width and intensity, and the variability of conventional absorption lines of the donor atmosphere. This is true for the phase variability of the absolute flux in the H$\alpha$ emission line and the fast varying of the continuum in the H$\alpha$ region as certain parameters, which reflect the phase variability of the donor magnetic field. This approach made it possible to determine the phase boundaries of the location of the magnetic polar region on the donor surface above which the matter outflows are formed.

Formation of magnetized spatial structures in the Beta Lyrae system. I. Observation as a research background of this phenomenon

The discovery of the donor magnetic field has repeatedly posed the task of a thorough study of the phenomenon, which is based on the concept of the influence of the magnetic field on the processes of the formation of gaseous structures and mass transfer in the Beta Lyrae system. This article provides an overview, analysis, and synthesis of the results of a variety of long-term observations as a necessary basis for further clarification of issues aimed primarily at the study of magnetized gaseous structures. As a part of such a study, it was found that the structure of the gaseous flows between the donor and the gainer varies in some way depending on the phases of the orbital period; and, accordingly, that the donor magnetic field influences the formation of these moving magnetized structures. The analysis of the masses of both components for use in further scientific works suggests that the following values are optimal: 2.9 M_sun for the donor and 13 M_sun for the gainer. The study of satellite lines as a certain phenomenon leads to the fact that the accretion disk surrounding the gainer consists of two parts: the external satellite disk and the internal massive opaque disk. From the analysis of all observations and studies of the magnetic field, observations on the 6-m telescope can be considered the most reliable. They have formed the spatial configuration of the donor magnetic field, which is important for studying and understanding the features of the mass transfer in this interacting system. Further evidence regarding the picture of the magnetized accretion structures as the special phenomenon will be presented in the following articles.

Evolutionary Study of Binary Star Beta Lyr

We present the evolutionary track of Beta Lyrae (β Lyr), an interacting eclipsing binary star, with orbital rotation period of 12.94 days, with one component known as the B-emission (Be) star. The primary star is a B6-B8II of 3M⊙ and the secondary is a 13M⊙ B0.5V star. The secondary star is embedded in the accretion disc produced by the infalling matter from the primary star, and this disc is estimated as the source of the emission lines. The evolution of the β Lyr system is simulated by using MESA software with the MESAbinary programming code. We obtain that the age of the binary system is 2.7 × 107 years, mass and radius of the primary component are M1 = 3.54M⊙, R1 = 16.1R⊙, and mass and radius of the secondary component are M2 = 13.1M⊙, R2 = 6.85R⊙.

X-ray binary Beta Lyrae and its donor component structure

AbstractWe show that the structure of magnetized accretion gas flows between the components of the Beta Lyrae system can cause a scattering gas shell that masks completely these components in soft X-ray region. Also we have calculated the inner structure of the donor that is filling a Roche lobe and is preceding a forming of the degenerate dwarf. We show that mass of the degenerate core of the donor is in region 0.3−0.5M⊙.

The complex circumstellar and circumbinary environment of V356 Sgr

We analyze 45 spectropolarimetric observations of the eclipsing, interacting binary star V356 Sgr, obtained over a period of 21 years, to characterize the geometry of the system's circumstellar material. After removing interstellar polarization from these data, we find the system exhibits a large intrinsic polarization signature arising from electron scattering. In addition, the lack of repeatable eclipses in the polarization phase curves indicates the presence of a substantial pool of scatterers not occulted by either star. We suggest that these scatterers form either a circumbinary disk coplanar with the gainer's accretion disk or an elongated structure perpendicular to the orbital plane of V356 Sgr, possibly formed by bipolar outflows. We also observe small-scale, cycle-to-cycle variations in the magnitude of intrinsic polarization at individual phases, which we interpret as evidence of variability in the amount of scattering material present within and around the system. This may indicate a mass transfer or mass loss rate that varies on the time-scale of the system's orbital period. Finally, we compare the basic polarimetric properties of V356 Sgr with those of the well studied beta Lyr system; the significant differences observed between the two systems suggests diversity in the basic circumstellar geometry of Roche-lobe overflow systems

REVISION OF THE PHENOMENOLOGICAL CHARACTERISTICS OF THE ALGOL-TYPE STARS USING THE NAV ALGORITHM

Phenomenological characteristics of the sample of the Algol-type stars are revised using a recently developed NAV (New Algol Variable) algorithm (2012Ap.....55..536A, 2012arXiv 1212.6707A) and compared to that obtained using common methods of Trigonometric Polynomial Fit (TP) or local Algebraic Polynomial (A) fit of a fixed or (alternately) statistically optimal degree (1994OAP.....7...49A, 2003ASPC..292..391A). The computer program NAV is introduced, which allows to determine the best fit with 7 linear and 5 non-linear parameters and their error estimates. The number of parameters is much smaller than for the TP fit (typically 20-40, depending on the width of the eclipse, and is much smaller (5-20) for the W UMa and beta Lyrae - type stars. This causes more smooth approximation taking into account the reflection and ellipsoidal effects (TP2) and generally different shapes of the primary and secondary eclipses. An application of the method to two-color CCD photometry to the recently discovered eclipsing variable 2MASS J18024395 + 4003309 = VSX J180243.9 +400331 (2015JASS...32..101A) allowed to make estimates of the physical parameters of the binary system based on the phenomenological parameters of the light curve. The phenomenological parameters of the light curves were determined for the sample of newly discovered EA and EW - type stars (VSX J223429.3+552903, VSX J223421.4+553013, VSX J223416.2+553424, US-NO-B1.0 1347-0483658, UCAC3-191-085589, VSX J180755.6+074711= UCAC3 196-166827). Despite we have used original observations published by the discoverers, the accuracy estimates of the period using the NAV method are typically better than the original ones.

On the accretion disc and evolutionary stage of β Lyrae

We modeled the V-band light curve of beta Lyrae with two stellar components plus an optically thick accretion disc around the gainer assuming a semidetached configuration. We present the results of this calculation, giving physical parameters for the stars and the disc, along with general system dimensions. We discuss the evolutionary stage of the system finding the best match with one of the evolutionary models of Van Rensbergen et al. According to this model, the system is found at age 2.30E7 years, in the phase of rapid mass transfer, the second one in the life of this binary, in a Case-B mass-exchange stage with dM/dt = 1.58E-5 Msun/year. This result, along with the reported rate of orbital period change and observational evidence of mass loss, suggests that the mass transfer in beta Lyrae, is quasi-conservative. The best model indicates that beta Lyrae finished a relatively large mass loss episode 31400 years ago. The light curve model that best fit the observations has inclination angle i = 81 degree, M1 = 13.2 Msun, M2 = 3.0 Msun, R1 = 6.0 Rsun and R2 = 15.2 Rsun. The disc contributes 22% to the total V-band light curve at quadrature, has a radius of 28.3 Rsun and the outer edge thickness is 11.2 Rsun. The light curve model is significantly better with two bright regions in the disc rim with temperatures 10% and 20% higher than the disc outer edge temperature. We compare our results with earlier studies of this interacting binary.

Constraining the Mass Loss Geometry of Beta Lyrae

Massive binary stars lose mass by two mechanisms: jet-driven mass loss during periods of active mass transfer and by wind-driven mass loss. Beta Lyrae is an eclipsing, semi-detached binary whose state of active mass transfer provides a unique opportunity to study how the evolution of binary systems is affected by jet-driven mass loss. Roche lobe overflow from the primary star feeds the thick accretion disk which almost completely obscures the mass-gaining star. A hot spot predicted to be on the edge of the accretion disk may be the source of beta Lyrae's bipolar outflows. I present results from spectropolarimetric data taken with the University of Wisconsin's Half-Wave Spectropolarimeter and the Flower and Cook Observatory's photoelastic modulating polarimeter instrument which have implications for our current understanding of the system's disk geometry. Using broadband polarimetric analysis, I derive new information about the structure of the disk and the presence and location of a hot spot. These results place constraints on the geometrical distribution of material in beta Lyrae and can help quantify the amount of mass lost from massive interacting binary systems during phases of mass transfer and jet-driven mass loss.

The evolution stage and massive disc of the interacting binary V 393 Scorpii

V393 Scorpii is a bright Galactic Double Periodic Variable showing a long photometric cycle of approx. 253 days. We present new VIJK photometric time series for V393 Scorpii along with the analysis of ASAS V-band photometry. We disentangled all light curves into the orbital and long cycle components. The ASAS V-band orbital light curve was modeled with two stellar components plus a circumprimary optically thick disc assuming a semidetached configuration. We present the results of this calculation, giving physical parameters for the stars and the disc, along with general system dimensions. Our results are in close agreement with those previously found by Mennickent et al. (2010) from IR spectroscopy and the modeling of the spectral energy distribution. The stability of the orbital light curve suggests that the stellar + disc configuration remains stable during the long cycle. Therefore, the long cycle should be produced by an additional variable and not-eclipsed emitting structure. We discuss the evolutionary stage of the system finding the best match with one of the evolutionary models of van Rensbergen et al. (2008). According to these models, the system is found to be after an episode of fast mass exchange that transferred 4 M_sun from the donor to the gainer in a period of 400.000 years. We argue that a significant fraction of this mass has not been accreted by the gainer but remains in an optically thick massive (about 2 M_sun) disc-like surrounding pseudo-photosphere whose luminosity is not driven by viscosity but probably by reprocessed stellar radiation. Finally, we provide the result of our search for Galactic Double Periodic Variables and briefly discuss the outliers beta Lyr and RX Cas.

The first search for variable stars in the open cluster NGC 6253 and its surrounding field

This work presents the first high-precision variability survey in the field of the intermediate-age, metal--rich open cluster NGC 6253. Clusters of this type are benchmarks for stellar evolution models. Continuous photometric monitoring of the cluster and its surrounding field was performed over a time span of ten nights using the Wide Field Imager mounted at the ESO-MPI 2.2m telescope. High-quality timeseries, each composed of about 800 datapoints, were obtained for 250,000 stars using ISIS and DAOPHOT packages. Candidate members were selected by using the colour-magnitude diagrams and period-luminosity-colour relations. Membership probabilities based on the proper motions were also used. The membership of all the variables discovered within a radius of 8 arcmin from the centre is discussed by comparing the incidence of the classes in the cluster direction and in the surrounding field. We discovered 595 variables and we also characterized most of them providing their variability classes, periods, and amplitudes. The sample is complete for short periods: we classified 20 pulsating variables, 225 contact systems, 99 eclipsing systems (22 Beta Lyr type, 59 Beta Per type, 18 RS CVn type), and 77 rotational variables. The time-baseline hampered the precise characterization of 173 variables with periods longer than 4-5 days. Moreover, we found a cataclysmic system undergoing an outburst of about 2.5 mag. We propose a list of 35 variable stars (8 contact systems, 2 eclipsing systems, 15 rotational variables, 9 long-period variables and the cataclysmic variable) as probable members of NGC 6253.

Eclipsing and density effects on the spectral behavior of Beta Lyrae binary system in the UV

We analyze both long and short high resolution ultraviolet spectrum of Beta Lyrae eclipsing binary system observed with the International Ultraviolet Explorer (IUE) between 1980 and 1989. The main spectral features are P Cygni profiles originating from different environments of Beta Lyrae. A set of 23Mg II k&h spectral lines at 2800Å, originating from the extended envelope [Hack, M., 1980. IAUS, 88, 271H], have been identified and measured to determine their fluxes and widths. We found that there is spectral variability for these physical parameters with phase, similar to that found for the light curve [Kondo, Y., McCluskey, G.E., Jeffery, M.M.S., Ronald, S.P., Carolina, P.S. McCluskey, Joel, A.E., 1994. ApJ, 421, 787], which we attribute to the eclipse effects [Ak, H., Chadima, P., Harmanec, P., Demircan, O., Yang, S., Koubský, P., Škoda, P., Šlechta, M., Wolf, M., Božić, H., 2007. A&A, 463, 233], in addition to the changes of density and temperature of the region from which these lines are coming, as a result of the variability of mass loss from the primary star to the secondary [Hoffman, J.L., Nordsieck, K.H., Fox, G.K., 1998. AJ, 115, 1576; Linnell, A.P., Hubeny, I., Harmanec, P., 1998. ApJ, 509, 379]. Also we present a study of Fe II spectral line at 2600Å, originating from the atmosphere of the primary star [Hack, M., 1980. IAUS, 88, 271H]. We found spectral variability of line fluxes and line widths with phase similar to that found for Mg II k&h lines. Finally we present a study of Si IV spectral line at 1394Å, originating from the extended envelope [Hack, M., 1980. IAUS, 88, 271H]. A set of 52 Si IV spectral line at 1394Å have been identified and measured to determine their fluxes and widths. Also we found spectral variability of these physical parameters with phase similar to that found for Mg II k&h and Fe II spectral lines.

First Resolved Images of the Eclipsing and Interacting Binary β Lyrae

We present the first resolved images of the eclipsing binary Beta Lyrae, obtained with the CHARA Array interferometer and the MIRC combiner in the H band. The images clearly show the mass donor and the thick disk surrounding the mass gainer at all six epochs of observation. The donor is brighter and generally appears elongated in the images, the first direct detection of photospheric tidal distortion due to Roche-lobe filling. We also confirm expectations that the disk component is more elongated than the donor and is relatively fainter at this wavelength. Image analysis and model fitting for each epoch were used for calculating the first astrometric orbital solution for Beta Lyrae, yielding precise values for the orbital inclination and position angle. The derived semi-ma jor axis also allows us to estimate the distance of Beta Lyrae; however, systematic differences between the models and the images limit the accuracy of our distance estimate to about 15%. To address these issues, we will need a more physical, self-consistent model to account for all epochs as well as the multi-wavelength information from the eclipsing light curves.

Phase-dependent X-ray observations of the β Lyrae system

We report on observations of the eclipsing and interacting binary beta Lyrae from the Suzaku X-ray telescope. This system involves an early B star embedded in an optically and geometrically thick disk that is siphoning atmospheric gases from a less massive late B II companion. Motivated by an unpublished X-ray spectrum from the Einstein X-ray telescope suggesting unusually hard emission, we obtained time with Suzaku for pointings at three different phases within a single orbit. From the XIS detectors, the softer X-ray emission appears typical of an early-type star. What is surprising is the remarkably unchanging character of this emission, both in luminosity and in spectral shape, despite the highly asymmetric geometry of the system. We see no eclipse effect below 10 keV. The constancy of the soft emission is plausibly related to the wind of the embedded B star and Thomson scattering of X-rays in the system, although it might be due to extended shock structures arising near the accretion disk as a result of the unusually high mass-transfer rate. There is some evidence from the PIN instrument for hard emission in the 10-60 keV range. Follow-up observations with the RXTE satellite will confirm this preliminary detection.

A Spectroscopic Study of Mass Outflows in the Interacting Binary RY Scuti

The massive interacting binary RY Scuti is an important representative of an active mass-transferring system that is changing before our eyes and which may be an example of the formation of a Wolf-Rayet star through tidal stripping. Utilizing new and previously published spectra, we present examples of how a number of illustrative absorption and emission features vary during the binary orbit. We identify spectral features associated with each component, calculate a new, double-lined spectroscopic binary orbit, and find masses of 7.1 +/- 1.2 M_sun for the bright supergiant and 30.0 +/- 2.1 M_sun for the hidden massive companion. Through tomographic reconstruction of the component spectra from the composite spectra, we confirm the O9.7 Ibpe spectral class of the bright supergiant and discover a B0.5 I spectrum associated with the hidden massive companion; however, we suggest that the latter is actually the spectrum of the photosphere of the accretion torus immediately surrounding the massive companion. We describe the complex nature of the mass loss flows from the system in the context of recent hydrodynamical models for beta Lyr, leading us to conclude RY Scuti has matter leaving the system in two ways: 1) a bipolar outflow from winds generated by the hidden massive companion, and 2) mass from the bright O9.7 Ibpe supergiant flowing from the region near the L2 point to fill out a large, dense circumbinary disk. This circumbinary disk (radius ~ 1 AU) may feed the surrounding double-toroidal nebula (radius ~ 2000 AU).

Spectrophotometry of some lines in Beta Lyrae

A spectrophotometric study of the spectral lines Hγ, He I λ 4388 A, He I λ 4472 A, Fe II λ 4352 A and Mg II λ 4481 A in the spectrum of β Lyrae has been made by using fifteen spectra taken with a spectrograph (8 A/mm) attached to the 1-metre reflector of the Hamburger Sternwarte. The profiles of the above lines are given. Also the probable variations of these profiles with time are examined on the basis of a comparison of our observational data with data existing in the literature. More attention was paid to the emission components of Hγ and the Helium lines. The views previously described in a general way by Sahade as to the structure of the emission lines are rather supported.

40 years observations and secondary rhythms in Beta Lyrae system

40 years observations and secondary rhythms in Beta Lyrae system

The origin of the radio emission from β Lyrae

In this paper we present new observational evidence that supports the presence of an extra source of continuum emission in the binary system beta Lyrae. New VLA and IRAM observations, together with published data from the literature and ISO archive data, allow us to build the Spectral Energy Distribution of the binary between 5x10^9 Hz and 5x10^15Hz. The radio-millimeter part of the spectrum is consistent with free-free emission from a symbiotic-like wind associated with the primary component and ionized by the radiation field of the hidden companion. Furthermore, we also consider the possibility that the observed radio flux originates from collimated radio structures associated with the mass gaining component and its disk (Conical thermal jets). An extrapolation of this emission to the far-IR part of the spectrum indicates that in both cases the free-free contribution at these frequencies cannot explain the observations and that the observed infrared excess flux is due principally to the secondary component and its associated disk.

The 283-Day Periodicity in the O-C Diagram of Beta Lyrae

A detailed analysis of an extensive collection of primary visual, photographic and photoelectric minima of Beta Lyrae was performed. After removing the effect of the increase in orbital period we applied the Fourier analysis to the 0-C residuals. The most prominent periodicity is 283 days with amplitude about 0.05 days. It confirms the period found in the photometric light curves of Beta Lyrae [Van Hamme, Wilson and Guinan (1995)]. The 283-d quasi-variation of the period may be explained by assymetries of the light curve near the minima caused by some instabilities in disc and/or hot spot(s) brightness.

Ultraviolet light curves of beta Lyrae: Comparison of OAO A-2, IUE, and Voyager Observations

view Abstract Citations (21) References (17) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Ultraviolet Light Curves of beta Lyrae: Comparison of OAO A-2, IUE, and Voyager Observations Kondo, Yoji ; McCluskey, George E. ; Silvis, Jeffery M. S. ; Polidan, Ronald S. ; McCluskey, Carolina P. S. ; Eaton, Joel A. Abstract The six-band ultraviolet light curves of beta Lyrae obtained with the Orbiting Astronomical Observatory (OAO) A-2 in 1970 exhibited a very unusual behavior. The secondary minimum deepened at shorter wavelength, indicating that one was not observing light variations caused primarily by the eclipses of two stars having a roughly Planckian energy distribution. It was then suggested that the light variations were caused by a viewing angle effect of an optically thick, ellipsoidal circumbinary gas cloud. Since 1978 beta Lyrae has been observed with the International Ultraviolet Explorer (IUE) satellite. We have constructed ultraviolet light curves from the IUE archival data for comparison with the OAO A-2 results. We find that they are in substantial agreement with each other. The Voyager ultraviolet spectrometer was also used to observe this binary during a period covered by IUE observations. The Voyager results agree with those of the two other satellite observatories at wavelengths longer than about 1350 A. However, in the wavelength region shorter than the Lyman-alpha line at 1216 A, the light curves at 1085 and 965 A show virtually no light variation except an apparent flaring near phase 0.7, which is also in evidence at longer wavelengths. We suggest that the optically thick circumbinary gas cloud, which envelops the two stars completely, assumes a roughly spherical shape when observed at these shorter wavelengths. Publication: The Astrophysical Journal Pub Date: February 1994 DOI: 10.1086/173691 Bibcode: 1994ApJ...421..787K Keywords: Eclipsing Binary Stars; Light Curve; Spaceborne Astronomy; Stellar Envelopes; Stellar Spectra; Ultraviolet Astronomy; Ultraviolet Spectra; Astronomical Spectroscopy; Oao 2; Voyager Project; Astronomy; STARS: BINARIES: ECLIPSING; STARS: CIRCUMSTELLAR MATTER; STARS: INDIVIDUAL CONSTELLATION NAME: BETA LYRAE; ULTRAVIOLET: STARS full text sources ADS | data products SIMBAD (6) MAST (1) INES (1)