Orbital eccentricity of the symbiotic star MWC 560

Zamanov, R.; Gomboc, A.; Stoyanov, K. A.; Статева, И.

doi:10.1002/asna.200911297

Cited by 5 publications

(6 citation statements)

References 30 publications

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“…The modulation at the binary period P2 is primarily due to the eccentricity of the binary orbit. Zamanov et al (2010) We now suggest that the P3=722 d is the sidereal rotation period of the giant. The second The period P4=1150 d satisfies P4=1/(1/P3-1/P2) (See Table 3), i.e.…”

Section: Qualitative Modelmentioning

confidence: 77%

“…The modulation at the binary period P2 is primarily due to the eccentricity of the binary orbit. Zamanov et al (2010) estimated it to be as high as 0.68. Close to periastron passages of the system, the L1 point of its equi-potential Roche lobes is getting closer to the giant center, exposing deeper layers of the giant atmosphere to the gravitational pool of the companion.…”

Section: Qualitative Modelmentioning

confidence: 99%

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Three Fundamental Periods in an 87 Year Light Curve of the Symbiotic Star MWC 560

Leibowitz¹,

Formiggini²

2015

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We have constructed a visual light curve of the symbiotic star MWC covering the last 87 years of its history. The data were assembled from the literature and from the AAVSO data bank. Most of the periodic components of the system brightness variation can be accounted for by the operation of 3 basic clocks of the periods P1=19000 d, P2=1943 d and P3=722 d. These periods can plausibly, and consistently with the observations, be attributed to 3 physical mechanisms in the system. They are, respectively, the working of a solar-like magnetic dynamo cycle in the outer layers of the giant star of the system, the binary orbit cycle and the sidereal rotation cycle of the giant star. MWC 560 is the 7 th symbiotic star with historical light curves that reveal similar basic characteristics of the systems. The light curves of all these stars are well interpreted on the basis of current understanding of the physical processes that are the major sources of the optical luminosity of these symbiotic systems.

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Section: Qualitative Modelmentioning

confidence: 77%

Section: Qualitative Modelmentioning

confidence: 99%

Three Fundamental Periods in an 87 Year Light Curve of the Symbiotic Star MWC 560

Leibowitz¹,

Formiggini²

2015

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“…Using high-resolution spectroscopic observations and the cross-correlation function method, Zamanov et al (2007) find a typical rotational velocity of the K and M giants in S-type symbiotic stars to be 4.5 < v rot sin(i) < 11.7 km s −1 . These results were confirmed by Zamanov & Stoyanov (2012). Using new data for 55 field M0 III -M6 III giants, they indicated a mean v rot sin(i) = 5.0 km s −1 and median v rot sin(i) = 4.3 km s −1 .…”

Section: Parameters Of the Rg Windmentioning

confidence: 52%

Wind mass transfer in S-type symbiotic binaries I. Focusing by the wind compression model

Skopal,

Carikova

2014

Preprint

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Context. Luminosities of hot components in symbiotic binaries require accretion rates that are higher than those that can be achieved via a standard Bondi-Hoyle accretion. This implies that the wind mass transfer in symbiotic binaries has to be more efficient. Aims. We suggest that the accretion rate onto the white dwarfs (WDs) in S-type symbiotic binaries can be enhanced sufficiently by focusing the wind from their slowly rotating normal giants towards the binary orbital plane. Methods. We applied the wind compression model to the stellar wind of slowly rotating red giants in S-type symbiotic binaries. Results. Our analysis reveals that for typical terminal velocities of the giant wind, 20 to 50 km s −1 , and measured rotational velocities between 6 and 10 km s −1 , the densities of the compressed wind at a typical distance of the accretor from its donor correspond to the mass-loss rate, which can be a factor of ∼10 higher than for the spherically symmetric wind. This allows the WD to accrete at rates of 10 −8 − 10 −7 M ⊙ yr −1 , and thus to power its luminosity. Conclusions. We show that the high wind-mass-transfer efficiency in S-type symbiotic stars can be caused by compression of the wind from their slowly rotating normal giants, whereas in D-type symbiotic stars, the high mass transfer ratio can be achieved via the gravitational focusing, which has recently been suggested for very slow winds in Mira-type binaries.

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“…Another possibility how to compress the wind from a star to the equatorial plane is the rotation of the central star (Bjorkman and Cassinelli , 1993). Zamanov and Stoyanov (2012) found that giants in symbiotic stars rotate with a mean v sin(i) ∼ 8 km s −1 . Using this value and other characteristic parameters of the giant's wind in symbiotic stars (e.g.Ṁ giant,wind ∼ 10 −7 M ⊙ yr −1 as above and terminal velocity of 20-40 km s −1 ), the wind compression at the orbital plane and a distance of 2-3 A.U.…”

Section: On the Accretion Mechanismmentioning

confidence: 99%

Multiwavelength modeling the SED of supersoft X-ray sources III. RS Ophiuchi: The supersoft X-ray phase and beyond

Skopal

2015

New Astronomy

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-Multiwavelength model SEDs of the nova RS Oph from X-rays to mid-IR were performed. -During the supersoft source phase its luminosity was highly super-Eddington. -It was sustained by a high accretion rate from a disk, followed by jets. -During quiescence the SED satisfied radiation produced by a large accretion disk. -The high accretion rate could be realized throughout a focused wind of the giant. AbstractI modelled the 14Å-37 µm SED of the recurrent symbiotic nova RS Oph during its supersoft source (SSS) phase and the following quiescent phase. During the SSS phase, the model SEDs revealed the presence of a strong stellar and nebular component of radiation in the spectrum. The former was emitted by the burning WD at highly super-Eddington rate, while the latter represented a fraction of its radiation reprocessed by the thermal nebula. During the transition phase, both the components were decreasing and during quiescence the SED satisfied radiation produced by a large, optically thick disk (R disk > 10 R⊙). The super-Eddington luminosity of the burning WD during the SSS phase was independently justified by the high quantity of the nebular emission. The emitting material surrounded the burning WD, and its mass was (1.6 ± 0.5) × 10 −4 (d/1.6 kpc) 5/2 M⊙. The helium ash, deposited on the WD surface during the whole burning period, was around of 8 × 10 −6 (d/1.6 kpc) 2 M⊙, which yields an average growing rate of the WD mass,ṀWD ∼ 4 × 10 −7 (d/1.6 kpc) 2 M⊙ yr −1 . The mass accreted by the WD between outbursts, macc ∼ 1.26 × 10 −5 M⊙, constrains the average accretion rate,Ṁacc ∼ 6.3 × 10 −7 M⊙ yr −1 . During quiescence, the accretion rate from the model SED of ∼ 2.3 × 10 −7 M⊙ yr −1 requires a super-Eddington accretion from the disk at ∼ 3.6 × 10 −5 M⊙ yr −1 during the outburst. Such a high accretion can be responsible for the super-Eddington luminosity during the whole burning phase. Simultaneous presence of jets supports this scenario. If the wind from the giant is not sufficient to feed the WD at the required rate, the accretion can be realized from the disk-like reservoir of material around the WD. In this case the time between outbursts will extend, with the next explosion beyond 2027. In the opposite case, the wind from the giant has to be focused to the orbital plane to sustain the high accretion rate at a few ×10 −7 M⊙ yr −1 . Then the next explosion can occur even prior to 2027.

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Orbital eccentricity of the symbiotic star MWC 560

Cited by 5 publications

References 30 publications

Three Fundamental Periods in an 87 Year Light Curve of the Symbiotic Star MWC 560

Three Fundamental Periods in an 87 Year Light Curve of the Symbiotic Star MWC 560

Wind mass transfer in S-type symbiotic binaries I. Focusing by the wind compression model

Multiwavelength modeling the SED of supersoft X-ray sources III. RS Ophiuchi: The supersoft X-ray phase and beyond

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