Eclipsing binary UU Cas: Radial-velocity curves

Gorda, S. Yu.

doi:10.1134/s1990341317030208

Cited by 11 publications

(25 citation statements)

References 4 publications

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“…We have chosen a somewhat wider range for the third light contribution of l 3 =±0.3. To take into account the uncertainty of the binary velocity curve, we varied the radial velocity shifts of theoretical spectra by ΔV with respect to the velocity curve constructed by Gorda (2017). We varied ΔV from −10 to 10 kms −1 , which is consistent with the rms deviation of ∼10 kms −1 of the line velocity shifts from the velocity curve estimated by Gorda (2017).…”

Section: Fitting Balmer Photospheric Absorption Line Profilesmentioning

confidence: 73%

“…In this study, we use the spectra obtained by Gorda (2017) 2017 January-April as well as new spectra obtained 2017 July through 2018 March. A summary of the observational data is given in Table 1 where the phase has been calculated from the following equation (Gorda 2017), taking into account that we utilize the phases shifted by 0.5 from those in Gorda (2017)…”

Section: Observations Data Reduction and Spectral Analysismentioning

confidence: 99%

“…To take into account the uncertainty of the binary velocity curve, we varied the radial velocity shifts of theoretical spectra by ΔV with respect to the velocity curve constructed by Gorda (2017). We varied ΔV from −10 to 10 kms −1 , which is consistent with the rms deviation of ∼10 kms −1 of the line velocity shifts from the velocity curve estimated by Gorda (2017). We, therefore, calculated the radial velocities of the primary, V r1 , and secondary, V r2 , as…”

Section: Fitting Balmer Photospheric Absorption Line Profilesmentioning

confidence: 99%

“…Therefore, it is important, inter alia, to investigate the gas dynamic pattern in a system and reveal the details of the mass transfer process to understand its evolutionary state and further evolutionary path. In this paper, we continue the study initiated by Gorda (2017) and focus on the gas dynamic features of the UUCas system, since these features significantly contribute to the observational data, both photometric and spectroscopic, and may give information on system's evolutionary scenario. Herein, we use spectral data and Doppler tomography to describe the UUCas flow pattern in detail.…”

Section: Introductionmentioning

confidence: 98%

“…In 2017, Gorda (2017) conducted a detailed spectroscopic study of UUCas. The data he obtained allowed for the construction of the first velocity curves for both of the components of the binary by using the absorption He I and N II lines.…”

Section: Introductionmentioning

confidence: 99%

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On the Gas Dynamic Features of the Interacting Binary System UU Cas

Kononov

Gorda

Parfenov

2019

ApJ

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We present the results of spectroscopic observations and Hα Doppler tomography of the massive close binary system UUCas where a giant star fills its Roche lobe (donor) and transfers material through the vicinity of the L 1 point onto a massive but rather compact stellar companion (accretor). The system has been observed at the 1.2 m telescope of the Kourovka Astronomical Observatory. By analyzing the obtained spectra and computed Doppler tomogram, we suggest that at least three elements of the gas dynamic pattern in the system contribute to the Balmer Hα emission line profiles. These elements are: the stream from the L 1 point, the stellar wind from the accretor, and the diffuse disk, surrounding the accretor. In combination with the estimates of the companions' masses, our findings indicate that the system is at the late stage of the first mass transfer phase of its evolution.

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Section: Fitting Balmer Photospheric Absorption Line Profilesmentioning

confidence: 73%

Section: Observations Data Reduction and Spectral Analysismentioning

confidence: 99%

Section: Fitting Balmer Photospheric Absorption Line Profilesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

On the Gas Dynamic Features of the Interacting Binary System UU Cas

Kononov

Gorda

Parfenov

2019

ApJ

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New insights on the massive interacting binary UU Cassiopeiae

Mennickent

Djurašević

Vince

et al. 2020

A&A

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We present the results of our study of the close binary UU Cassiopeiae based on previously published multiwavelength photometric and spectroscopic data. Based on eclipse timings from the last 117 years, we find an improved orbital period of Po = 8.d519296(8). In addition, we find a long cycle of length T ∼ 270 d in the Ic-band data. There is no evidence for orbital period change over the last century, suggesting that the rate of mass loss from the system or mass exchange between the stars is small. Sporadic and rapid brightness drops of up to ΔV = 0.3 mag are detected throughout the orbital cycle, and infrared photometry clearly suggests the presence of circumstellar matter. We model the orbital light curve of 11 published datasets, fixing the mass ratio and cooler star temperature from previous spectroscopic work: q = 0.52 and Tc = 22 700 K. We find a system seen at an angle of 74° with a stellar separation of 52 R⊙, a temperature for the hotter star of Th = 30 200 K and, for the hotter and cooler stars, respectively, stellar masses of 17.4 and 9 M⊙, radii of 7.0 and 16.9 R⊙, and surface gravities log g = 3.98 and 2.94. We find an accretion disk surrounding the more massive star that has a radius of 21 R⊙ and a vertical thickness at its outer edge of 6.5 R⊙; the disk nearly occults the hotter star. Two active regions hotter than the surrounding disk are found, one located roughly in the expected position where the stream impacts the disk and the other on the opposite side of the disk. Changes are observed in parameters of the disk and spots in different datasets.

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Spectroscopy of the massive interacting binary UU Cassiopeiae

Hadrava

Cabezas

Djurašević

et al. 2022

A&A

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Context. The eclipsing close binary UU Cas is an interacting massive double-periodic system with a gainer star partly hidden in an accretion disk. Aims. In order to study the physics of the accretion process in greater detail, along with the structure and dynamics of the circumstellar matter in the system, we supplement our previous results obtained from photometry with an analysis of the spectra of UU Cas. Methods. We collected all available spectra used in previous publications on UU Cas and we acquired new ones. The method of disentangling was applied to this set of spectra spanning the years 2008–2021. The orbital parameters were disentangled and a fit of the separated component spectra by synthetic ones has been used to determine the physical parameters of the component stars. We compared the results to models of the evolution of interacting binaries. Results. We found that in addition to the dominant role of the donor star and a weak contribution of the gainer, the line profiles are strongly influenced by the circumstellar matter. The absorption lines reveal a presence of a disk wind emanating above the orbital plane. The variability of Hα emission yields evidence of changes in the structure of the circumstellar matter on a timescale of several orbital periods.

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Eclipsing binary UU Cas: Radial-velocity curves

Cited by 11 publications

References 4 publications

On the Gas Dynamic Features of the Interacting Binary System UU Cas

On the Gas Dynamic Features of the Interacting Binary System UU Cas

New insights on the massive interacting binary UU Cassiopeiae

Spectroscopy of the massive interacting binary UU Cassiopeiae

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