UX Monocerotis as a W Serpentis binary

Sudar, D.; Harmanec, P.; Lehmann, H.; Yang, S.; Božić, H.; Ruždjak, Domagoj

doi:10.1051/0004-6361/201014920

Cited by 13 publications

(11 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In passing we note that we also independently tested the results from PHOEBE using the BINSYN suite of programs (Linnell 1984;Linnell & Hubeny 1996;Linnell 2000) with steepest descent method to optimise the parameters of the binary system (Sudar et al 2011). This basically confirmed the results obtained with PHOEBE.…”

Section: Combined Light-curve and Orbital Solution In Phoebesupporting

confidence: 74%

Properties and nature of Be stars

Koubský

Harmanec

Brož

et al. 2019

A&A

Self Cite

View full text Add to dashboard Cite

Reliable determination of the basic physical properties of hot emission-line binaries with Roche-lobe filling secondaries is important for developing the theory of mass exchange in binaries. It is not easy, however, due to the presence of circumstellar matter. Here, we report the first detailed investigation of a new representative of this class of binaries, HD 81357, based on the analysis of spectra and photometry from several observatories. HD 81357 was found to be a double-lined spectroscopic binary and an ellipsoidal variable seen under an intermediate orbital inclination of ∼(63 ± 5)°, having an orbital period of 33.d77445(41) and a circular orbit. From an automated comparison of the observed and synthetic spectra, we estimate the component’s effective temperatures to be 12930(540) K and 4260(24) K. The combined light-curve and orbital solutions, also constrained by a very accurate Gaia Data Release 2 parallax, give the following values of the basic physical properties: masses 3.36 ± 0.15 and 0.34 ± 0.04M⊙N, radii 3.9 ± 0.2 and 13.97 ± 0.05R⊙N, and a mass ratio 10.0 ± 0.5. Evolutionary modelling of the system including the phase of mass transfer between the components indicated that HD 81357 is a system observed in the final slow phase of the mass exchange after the mass-ratio reversal. Contrary to what has been seen for similar binaries like AU Mon, no cyclic light variations were found on a time scale an order of magnitude longer than the orbital period.

show abstract

Section: Combined Light-curve and Orbital Solution In Phoebesupporting

confidence: 74%

Properties and nature of Be stars

Koubský

Harmanec

Brož

et al. 2019

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…This class mainly corresponds to genuine Algol systems (including the prototype β Per; see Table 2). Sudar et al (2011); (4) Wilson & Starr (1976); (5) Lomax et al (2012); (6) Budding et al (2004); (7) Giuricin et al (1983); (8) Piirola et al (2005): mass-transfer rate derived from period-change rate (Ṗ/P = 14 s yr −1 ) assuming a conservative mass transfer.…”

Section: Classification Of Algol Systemsmentioning

confidence: 99%

Critically-rotating accretors and non-conservative evolution in Algols

Deschamps

Siess

Davis

et al. 2013

A&A

View full text Add to dashboard Cite

Context. During the mass-transfer phase in Algol systems, a large amount of mass and angular momentum are accreted by the gainer star, which can be accelerated up to its critical Keplerian velocity. The fate of the gainer once it reaches this critical value is unclear. Aims. We investigate the orbital and stellar spin evolution in semi-detached binary systems, specifically for systems with rapidly rotating accretors. Our aims are to better distinguish between the different spin-down mechanisms proposed that can consistently explain the slow rotation observed in Algols' final states and to assess the degree of non-conservatism due to the formation of a hotspot. Methods. We use our state-of-the-art binary evolution code, Binstar, which incorporates a detailed treatment of the orbital and stellar spin and includes all torques due to mass transfer, the interactions between a star and its accretion disc, tidal effects, and magnetic braking. We also present a new prescription for mass loss due to the formation of a hotspot based on energy conservation. Results. The coupling between the star and the disc via the boundary layer prevents the gainer from exceeding the critical rotation. Magnetic-field effects, although operating, are not the dominant spin-down mechanism for sensible field strengths. Spin down owing to tides is 2-4 orders of magnitudes too weak to compensate the spinning-up torque due to mass accretion. Moreover, we find that the final separation strongly depends on the spin-down mechanism. The formation of a hotspot leads to a large event of mass loss during the rapid phase of mass transfer. The degree of conservatism strongly depends on the opacity of the impacted material. Conclusions. A statistical study and new observational constraints are needed to find the optimal set of parameters (magnetic-field strength, hotspot geometry, etc.) to reproduce Algol evolutions.

show abstract

“…There are very few recognized examples of pre-mass reversal objects. We consider three such systems here: SX Aur (Linnell et al 1988), SV Cen (Drechsel et al 1982;Linnell & Scheick 1991), and UX Mon (Sudar et al 2011). The radius of the primary component in the SX Aur system is quite close to being in contact with its Roche surface, while its companion is unevolved.…”

Section: The Interacting Binary Landscapementioning

confidence: 99%

Ultraviolet Spectropolarimetry:Conservative and Nonconservative Mass Transfer in OB Interacting Binaries

Peters¹,

Gayley²,

Ignace³

et al. 2021

Preprint

View full text Add to dashboard Cite

One objective of the Polstar spectropolarimetry mission is to characterize the degree of nonconservative mass transfer that occurs at various stages of binary evolution, from the initial mass reversal to the late Algol phase. The proposed instrument combines spectroscopic and polarimetric capabilities, where the spectroscopy can resolve Doppler shifts in UV resonance lines with 10 km/s precision, and polarimetry can resolve linear polarization with 10 −3 precision or better. The spectroscopy will identify absorption by mass streams seen in projection against the stellar disk as a function of orbital phase, as well as scattering from extended splash structures and a circumbinary disk of material that fails to be transferred conservatively. The polarimetry affects more the light coming from material not seen against the stellar disk, allowing the geometry of the scattering to be tracked, resolving ambiguities left by the spectroscopy and light-curve information. For example, nonconservative mass streams ejected in the polar direction will produce polarization of the opposite sign from conservative transfer accreting in the orbital plane. Also, time domain coverage over a range of phases of the binary orbit are well supported by the Polstar observing strategy. Combining these elements will significantly improve our understanding of the mass transfer process and the amount of mass that can escape from the system, an important channel for changing the final mass, and ultimate supernova, of the large number of massive stars found in binaries at close enough separation to undergo interaction.

show abstract

UX Monocerotis as a W Serpentis binary

Cited by 13 publications

References 25 publications

Properties and nature of Be stars

Properties and nature of Be stars

Critically-rotating accretors and non-conservative evolution in Algols

Ultraviolet Spectropolarimetry:Conservative and Nonconservative Mass Transfer in OB Interacting Binaries

Contact Info

Product

Resources

About