Analysis of eleven late-type close binary systems.

1983 ◽  
Vol 95 ◽  
pp. 592
Author(s):  
K.-C. Leung ◽  
D. S. Zhai ◽  
R. X. Zhang ◽  
Q. Y. Liu ◽  
J. T. Zhang ◽  
...  
Author(s):  
K. C. Leung ◽  
D. S. Zhai ◽  
R. X. Zhang ◽  
Q. Y. Liu ◽  
J. T. Zhang ◽  
...  

1984 ◽  
Vol 99 (1-2) ◽  
pp. 411-411
Author(s):  
K. C. Leung ◽  
D. S. Zhai ◽  
R. X. Zhang ◽  
Q. Y. Liu ◽  
J. T. Zhang ◽  
...  

1989 ◽  
Vol 107 ◽  
pp. 370-370
Author(s):  
G. Umana ◽  
S. Catalano ◽  
M. Rodonó ◽  
D. M. Gibson

Radio emission from close binary systems has long been detected in Algol and other systems. RS CVn systems have been found to be the most powerful and active. The RS CVn binaries are also known to show strong chromosferic and transition region emission line fluxes, that are one or two orders of magnitude higher than those from single stars of similar spectral type. This enhanced activity seems to be connected to the rapid rotation due to the tidal interaction in the system. The Algol binaries are semi-detected close binary systems formed by an early type main sequence primary and a late type giant secondary, while in the RS CVn both components are late type stars of about the same mass, the secondary being a giant or subgiant.The Algol binaries and RS CVn differ also in their evolutionary history. However, since the spectral type and probably the internal structure of the secondary components of Algols appear to be similar to that of the secondaries of RS CVn systems, and they both are synchronous fast rotators in close binaries, we would also expect that the secondaries of Algol systems to show some kind of activity.


1980 ◽  
Vol 88 ◽  
pp. 23-26
Author(s):  
L. Mantegazza ◽  
P. Paolicchi ◽  
P. Farinella ◽  
F. Luzny

The analysis of the period distribution of eclipsing and spectroscopic binary systems shows the presence of some secundary maxima, which cannot depend on selection effects. These secundary maxima are mainly due to late type stars, as can be seen from the distribution curves for eclipsing binaries of various spectral types. The average separation of the components (in units of the sum of stellar radii) increases with the spectral type from 0 types to late B types, remaining almost constant for later spectral types.


1965 ◽  
Vol 5 ◽  
pp. 120-130
Author(s):  
T. S. Galkina

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.


1998 ◽  
Vol 11 (1) ◽  
pp. 398-398
Author(s):  
Kenji Tanabe

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.


1974 ◽  
Vol 3 ◽  
pp. 89-107
Author(s):  
M. J. Rees

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.


1987 ◽  
Vol 134 (1) ◽  
pp. 161-176 ◽  
Author(s):  
Masaomi Nakamura ◽  
Yasuhisa Nakamura

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