Synthetic Spectra of Cool, Roche Lobe-filling Stars in Close Binary Systems

SU UMa stars are one of subclasses of dwarf novae. Dwarf novae are semi-detached close binary systems in which a Roche-lobe filling red dwarf secondary loses matter and the white dwarf primary accretes it through the accretion disk. The main characteristics of SU UMa subclass is that they show two kinds of outbursts: normal outbursts and superoutbursts. In addition to the more frequent narrow outbursts of normal dwarf nova, SU UMa stars exhibit “superoutbursts”, in which stars reach about 1 magnitude brighter and stay longer than in normal outburst. Careful photometric studies during superoutburst have almost always revealed the “superhumps”: periodic humps in light curves with a period very close to the orbital period of the system. However, the most curious of all is that this superhump period is not exactly equal to the orbital period, but it is always longer by a few percent than the orbital period.

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Roche-lobe overflow in the vicinity of the inner Lagrangian point in close binary systems

Astronomy Reports ◽

10.1134/1.1374641 ◽

2001 ◽

Vol 45 (6) ◽

pp. 452-460 ◽

Cited By ~ 1

Author(s):

V. V. Nazarenko ◽

L. V. Glazunova ◽

V. G. Karetnikov

Keyword(s):

Binary Systems ◽

Roche Lobe ◽

Close Binary ◽

Lagrangian Point ◽

Close Binary Systems

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The Close Binary Frequency of Wolf-Rayet Stars as a Function of Metallicity in M31 and M33

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314006516 ◽

2014 ◽

Vol 9 (S307) ◽

pp. 127-128

Author(s):

Kathryn F. Neugent ◽

Philip Massey

Keyword(s):

Binary Systems ◽

Roche Lobe ◽

Close Binary ◽

Evolutionary Models ◽

Single Star ◽

Close Binary Systems

AbstractHere we investigate whether the inability of the Geneva evolutionary models to predict a large enough WC/WN ratio at high metallicities (while succeeding at lower metallicities) is due to their single star nature. We hypothesize that Roche-lobe overflow in close binary systems may produce a greater number of WC stars at higher metallicities. But, this would suggest that the frequency of close massive binaries is metallicity dependent. We now present our results based on observations of ~100 Wolf-Rayet binaries in the varying metallicity environments of M31 and M33.

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THE QUASI-ROCHE LOBE OVERFLOW STATE IN THE EVOLUTION OF CLOSE BINARY SYSTEMS CONTAINING A RADIO PULSAR

The Astrophysical Journal ◽

10.1088/0004-637x/798/1/44 ◽

2014 ◽

Vol 798 (1) ◽

pp. 44 ◽

Cited By ~ 15

Author(s):

O. G. Benvenuto ◽

M. A. De Vito ◽

J. E. Horvath

Keyword(s):

Binary Systems ◽

Roche Lobe ◽

Radio Pulsar ◽

Close Binary ◽

Close Binary Systems

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Some Results of the Spectroscopic Study of Four Close Binary Systems of Early Spectral Types

International Astronomical Union Colloquium ◽

10.1017/s025292110002755x ◽

1965 ◽

Vol 5 ◽

pp. 120-130

Author(s):

T. S. Galkina

Keyword(s):

Spectroscopic Study ◽

Spectral Type ◽

Spectroscopic Investigation ◽

Binary Systems ◽

Quantitative Information ◽

Close Binary ◽

Physical Parameters ◽

Absorption And Emission ◽

Close Binary Systems ◽

Quantitative Estimates

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

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Solitons in the Close Binary Systems

Highlights of Astronomy ◽

10.1017/s1539299600021481 ◽

1998 ◽

Vol 11 (1) ◽

pp. 398-398

Author(s):

Kenji Tanabe

Keyword(s):

Gravity Waves ◽

Binary Systems ◽

Kdv Equation ◽

Frame Of Reference ◽

Close Binary ◽

Flare Activity ◽

Lagrangian Point ◽

Nls Equation ◽

Close Binary Systems ◽

The Earth

Propagation of the surface waves of the lobe-filing components of close binary systems is investigated theoretically. Such waves are considered to be analogous to the gravity waves of water on the earth. As a result, the equations of the surface wave in the rotating frame of reference are reduced to the so-called Kortewegde Vries (KdV) equation and non-linear Schroedinger (NLS) equation according to its ”depth”. Each of these equations is known to have the solution of soliton. When this soliton is sent to the other component of the binary system through the Lagrangian point, it can give rise to the flare activity observed in some kinds of close binary systems.

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X-Ray Sources in Close Binary Systems

Highlights of Astronomy ◽

10.1017/s1539299600001842 ◽

1974 ◽

Vol 3 ◽

pp. 89-107

Author(s):

M. J. Rees

Keyword(s):

Binary Systems ◽

Close Binary ◽

Rapid Variability ◽

X Ray ◽

Close Binary Systems ◽

General Order ◽

Typical Distances ◽

Astronomical Research ◽

Orbital Periods ◽

Galactic Sources

The discovery by Giacconi and his colleagues of variable X-ray sources in close binary systems certainly ranks as one of the highlights of astronomical research during the last 3 years. These remarkable objects have already been extensively studied, by optical and radio observations as well as in the X-ray band; and they seem likely to prove as significant and far-reaching in their implications as pulsars.The ‘Third Uhuru Catalogue’ (Giacconi et al., 1973a) contains about 160 sources, of which about 100 lie in our Galaxy. Their distribution over the sky (together with other arguments) suggests that these sources have luminosities of the general order 1036–1038 erg s−1, and that their typical distances are ˜ 10kpc. These galactic sources generally display rapid variability. Little else is known about most of them, but they are probably of the same general class as systems such as Her X1, Cen X3, Cyg X1 and Cyg X3. These sources have been investigated in detail, and in all cases one infers a system where the X-ray source is orbiting around a relatively ordinary star. Six sources have been optically identified, and there are some others whose binary nature is established by the occurrence of an X-ray eclipse. Orbital periods range from 4.8 h (Cyg X3) up to ˜ 10 days.

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