scholarly journals Catalogues of Spectroscopic Binaries

1977 ◽  
Vol 35 ◽  
pp. 141-145
Author(s):  
Alan H. Batten
Keyword(s):  
Binary Systems ◽  
Fixed Interval ◽  
Critical Assessment ◽  
The Other ◽  
Spectroscopic Binaries ◽  
Orbital Elements ◽  
Spectroscopic Binary ◽  
Other Hand

There are two centres at which papers on spectroscopic binaries are filed and catalogues produced — Toulouse, France and Victoria, B.C., Canada. The aims of these two are somewhat different. At Toulouse a running file of all references to spectroscopic binaries is kept, and many workers have found the comprehensive series of Catalogues Complémentaires (e.g. Pedoussaut and Carquillat 1973) very useful. At Victoria, on the other hand, we concentrate more specifically on spectroscopic determinations of orbital elements, and our catalogue of them was a direct successor of the five such catalogues published by the Lick Observatory. While the Toulouse catalogues are comprehensive, we at Victoria try to make a critical assessment of each orbit we include, and we regard this as one of the most important aspects of our catalogues. Such a critical catalogue obviously cannot be published as frequently as are the Catalogues Complémentaires, which, just as their name implies, are complementary to the Victoria work. There is no fixed interval between the publication of successive Lick-Victoria catalogues. The five from Lick appeared at a mean interval of about a decade, but the transfer to Victoria delayed the appearance of the Sixth Catalogue (Batten 1967) to almost twenty years after that of the Fifth (Moore and Neubauer 1948). After another decade, the Sixth Catalogue is out of date and out of print, and we are well advanced on the preparation of a Seventh, which we hope will appear in 1977. The Sixth Catalogue contained orbital elements for 737 spectroscopic binary systems. About 200 (or 25 per cent) new systems have now to be added, and about one per cent of those already in should be deleted. In addition, new orbital information is available for over 100 of the systems already in the Sixth Catalogue.

scholarly journals A Critical Assessment on the Indonesian Free Visa Policy: a Neorealist Perspective

2020 ◽  
Vol 22 (1) ◽  
pp. 54
Author(s):  
Andry Indrady
Keyword(s):  
Public Perception ◽  
Economic Benefits ◽  
Critical Assessment ◽  
The State ◽  
Control Measures ◽  
The Other ◽  
Immigration Control ◽  
Other Hand ◽  
Visa Policy ◽  
The Ideal

This paper discusses the implementation of free visa policy in Indonesia from a neorealist perspective. By utilizing the perspective of interdependence sovereignty and domestic sovereignty, this paper critically assesses the implementation of the free visa policy in Indonesia. From the interdependence sovereignty perspective, which elaborates the economic benefits, reciprocal and security approaches the paper finds that the free visa policy in Indonesia has yet to formulate a rational and objective policy that would lead to potential security – order threat. On the other hand, from the domestic sovereignty perspective the paper finds that although the state performs its immigration control capabilities effectively, however the said immigration control measures are implemented at a rather repressive level, instead of at the ideal prevention level. In the end, the paper suggests further research that fills the gap from findings on the specific methods to enhance the state’s capability in managing challenges posed by the free visa policy in more detail, as well as providing a method to measure public perception on the performance of immigration control.

scholarly journals On the Distribution of Young Spectroscopic Binary Stars Over the Major Semiaxes of their Orbits

1982 ◽  
Vol 69 ◽  
pp. 129-131
Author(s):  
E.I. Popova ◽  
A.V. Tutukov ◽  
B.M. Shustov ◽  
L.R. Yungelson
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Spectroscopic Binaries ◽  
Close Binary ◽  
Physical Parameters ◽  
Origin And Evolution ◽  
Spectroscopic Binary ◽  
Visible Spectra ◽  
Major Semiaxes ◽  
The Masses

About 60% of stars of the disc population in our Galaxy are close binary systems (CBS). Half of the known CBS are spectroscopic binary stars (Kraitcheva et al., 1978).To know the distribution of a correlation between the masses of CBS components and semiaxes of their orbits is necessary for the investigation of the origin and evolution of CBS. For such statistical investigations, a catalogue of CBS was compiled at the Astronomical Council. The catalogue is based on the 6th Batten catalogue (Batten, 1967), its extensions (Pedoussant and Ginestet, 1971; Pedoussant and Carquillat, 1973) and data published up to the end of 1980 (Popova et al., 1981). Now it is recorded on magnetic tape and contains data on 1041 spectroscopic binaries; 333 of them are stars with two visible spectra. The latter are mostly systems prior to mass exchange and the distribution of physical parameters in these systems reflects the distribution and presumably conditions at the time of formation. Using some assumptions, we can obtain for spectroscopic binaries masses of the components M1 and M2 (or the ratio q = M1/M2) and semiaxes of their orbits. Masses of components with the known sin i were obtained by the usual technique; when sin i was not known, masses were estimated from the spectra. We shall discuss here the distribution of CBS in the M-a plane.

Differential Enthalpies of Solution of Components in Binary Systems 2 CaO . Al2O3 . SiO2-CaO . Al2O3 . 2 SiO2, CaO . SiO2-CaO . Al2O3 . 2 SiO2 and CaO . SiO2-2 CaO . Al2O3 . SiO2

1993 ◽  
Vol 58 (9) ◽  
pp. 1989-1996 ◽  
Author(s):  
Ladislav Kosa ◽  
Ivan Nerád ◽  
Jozef Strečko ◽  
Ivo Proks ◽  
Katarína Adamkovičová
Keyword(s):  
Binary Systems ◽  
The Other ◽  
Enthalpies Of Solution ◽  
Heat Of Solution ◽  
Differential Heat ◽  
Temperature Range ◽  
Enthalpies Of Mixing ◽  
Other Hand ◽  
Temperature Dependences

Differential enthalpies of solution of components in binary systems 2 CaO . Al2O3 . SiO2-CaO . Al2O3 . 2 SiO2, CaO . SiO2-CaO . Al2O3 . 2 SiO2 and CaO . SiO2-2 CaO . Al2O3 . SiO2 as the function of composition and temperature were determined on the base of isothermal composition dependences of enthalpies of mixing and temperature dependences of heats of fusion of their pure components. From the values of the first differential heat of solution of CaO . Al2O3 . 2 SiO2 and 2 CaO . Al2O3 . SiO2 in CaO . SiO2 over temperature range considered we can conclude that the reactions were closed chains of SiO4 tetrahedra in CaO . SiO2 melt break, are exothermic. On the other hand positive values of this quantity for CaO . SiO2 in CaO . Al2O3 . 2 SiO2 and 2 CaO . Al2O3 . SiO2 led us to the conclusion that the progressive breaking originally closed chains in CaO . SiO2 melt has endothermic character.

scholarly journals The quest for collapsed/frozen stars in single-line spectroscopic binary systems

2014 ◽  
Vol 11 (S308) ◽  
pp. 38-45
Author(s):  
Virginia Trimble
Keyword(s):  
Black Holes ◽  
Binary Systems ◽  
Massive Star ◽  
Spectroscopic Binaries ◽  
Single Line ◽  
X Ray ◽  
Plausible Candidate ◽  
Spectroscopic Binary ◽  
Galactic Centers ◽  
X Ray Binaries

AbstractBlack holes are now commonplace, among the stars, in Galactic centers, and perhaps other places. But within living memory, their very existence was doubted by many, and few chose to look for them. Zeldovich and Guseinov were first, followed by Trimble and Thorne, using a method that would have identified HDE 226868 as a plausible candidate, if it had been in the 1968 catalogue of spectroscopic binaries. That it was not arose from an unhappy accident in the observing program of Daniel M. Popper long before the discovery of X-ray binaries and the identification of Cygnus X-1 with that hot, massive star and its collapsed companion.

scholarly journals Barium and related stars, and their white-dwarf companions

2019 ◽  
Vol 626 ◽  
pp. A127 ◽  
Author(s):  
A. Jorissen ◽  
H. M. J. Boffin ◽  
D. Karinkuzhi ◽  
S. Van Eck ◽  
A. Escorza ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Mass Distribution ◽  
White Dwarf ◽  
Binary Systems ◽  
Asymptotic Giant Branch ◽  
Spectroscopic Binaries ◽  
High Mass ◽  
Initial Mass ◽  
Mass Ratio ◽  
Orbital Elements

Context. Barium and S stars without technetium are red giants and are suspected of being members of binary systems due to their overabundances in heavy elements. These elements are produced by the s-process of nucleosynthesis, despite the stars not being evolved enough to be able to activate the s-process in their interiors. A companion formerly on the asymptotic giant branch (now a white dwarf) is supposed to be responsible for the barium- and S-star enrichment in s-process elements through mass transfer. Aims. This paper provides both long-period and revised orbits for barium and S stars, adding to previously published orbits. The sample of barium stars with strong anomalies (i.e., those classified as Ba3, Ba4, or Ba5 in the Warner scale) comprises all known stars of that kind, and in that sense forms a complete sample that allows us to investigate several orbital properties of these post-mass-transfer binaries in an unbiased way. Methods. Orbital elements are derived from radial velocities collected from a long-term radial-velocity monitoring campaign performed with the HERMES spectrograph mounted on the Mercator 1.2 m telescope. These new measurements were combined with older, CORAVEL measurements. With the aim of investigating possible correlations between orbital properties and abundances, we also collected a set of abundances for barium stars with orbital elements that is as homogeneous as possible. When unavailable in the literature, abundances were derived from high-resolution HERMES spectra. Results. We find orbital motion for all barium and extrinsic S stars monitored (except for the mild barium star HD 95345). We obtain the longest period known so far for a spectroscopic binary involving an S star, namely 57 Peg with a period of the order of 100−500 yr. We present the mass distribution for the barium stars, which ranges from 1 to 3 M⊙, with a tail extending up to 5 M⊙ in the case of mild barium stars. This high-mass tail is mostly comprised of high-metallicity objects ([Fe/H] ≥ −0.1). The distribution of the companion masses was extracted from the barium-star mass distribution combined with the finding that Q ≡ f(MBa,MWD)/sin3 i = MWD3/(MBa + MWD)2 is peaked at 0.057 ± 0.009 and 0.036 ± 0.027 M⊙ for strong and mild barium stars, respectively (f(MBa, MWD) is the mass function obtained from the orbital elements of spectroscopic binaries with one observable spectrum). Mass functions are compatible with WD companions whose masses range from 0.5 to 1 M⊙. Strong barium stars have a tendency to be found in systems with shorter periods than mild barium stars, although this correlation is rather lose, with metallicity and WD mass also playing a role. Using the initial–final mass relationship established for field WDs, we derived the distribution of the mass ratio q′=MAGB, ini/MBa (where MAGB, ini is the WD progenitor initial mass, i.e., the mass of the former primary component of the system) which is a proxy for the initial mass ratio (the less mass the barium star has accreted, the better the proxy). It appears that the distribution of q′ is highly nonuniform, and significantly different for mild and strong barium stars, the latter being characterized by values mostly in excess of 1.4, whereas mild barium stars occupy the range 1−1.4. Conclusions. The orbital properties presented in this paper pave the way for a comparison with binary-evolution and nucleosynthesis models, which should account for the various significant correlations found between abundances and dynamical parameters (e.g. between MBa on one hand and MWD, [Fe/H], and [s/Fe] on the other hand, between q′ and [s/Fe], between P and e, and between P and [s/Fe] altogether).

scholarly journals The Importance of the Lexical Paradigm of Pretext Assessment for the Formation of a Parody

2021 ◽  
Vol 7 (7) ◽  
pp. 6001-6005
Author(s):  
Olha Vorobiova ◽  
Keyword(s):  
Critical Appraisal ◽  
Critical Assessment ◽  
The Other ◽  
Original Text ◽  
Specific System ◽  
Other Hand ◽  
Paradigmatic Analysis ◽  
Distinguishing Features ◽  
Secondary Text

The article deals with transforming the primary text into a parody - the introduction of the paradigm of critical assessment of pretext into the primary text. This paradigm is derived using the paradigmatic analysis of vocabulary, highlighting the means of the text that form a specific system of images for the reader. Parody is of particular interest for the paradigmatic analysis of vocabulary since it refers to the so-called secondary texts - texts created on the material of other texts, already available. When creating a secondary text, various elements are borrowed from the original text, such as lexemes, phrases, etc., and lexical paradigms that undergo various transformations in the secondary text. However, a paradigm in parody is inherent exclusively in texts of this type - the paradigm of critical assessment of the pretext. A critical assessment of the pretext is extremely important for forming a parody since one of its main distinguishing features is controversial to the original text. To study the role of the critical appraisal paradigm, we took parodies of A. Ivanov on the verses of E. Yevtushenko. The study of this material has shown that the paradigm of critical assessment of the pretext is inherent exclusively in parodies and is used to form the effect of distancing the reader from the original text; pretext begins to be perceived not as a text itself, but as an object for outside consideration and criticism. The explicitly expressed paradigm of critical assessment of the pretext can also be accompanied by the paradigm of comic reduction, which forms a comic effect in parody, but this paradigm in the text is optional. On the other hand, critical assessment in the text is obligatory since it is due to this paradigm that polemic is formed, obligatory for parodic texts.

scholarly journals Spectroscopic Binaries in the LMC

1986 ◽  
Vol 116 ◽  
pp. 85-86
Author(s):  
Virpi S. Niemela
Keyword(s):  
Binary Systems ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Spectroscopic Binaries ◽  
Preliminary Results ◽  
Spectroscopic Binary ◽  
Stellar Masses

Preliminary results are presented of an observing programme aimed to obtain estimates of the stellar masses from studies of spectroscopic binary systems in the Large Magellanic Cloud. These are the first steps with the final purpose to determine an empirical mass-luminosity relation in a galaxy other than our own.

scholarly journals Searching for Earth-mass planets around α Centauri: precise radial velocities from contaminated spectra

2014 ◽  
Vol 14 (2) ◽  
pp. 173-176 ◽  
Author(s):  
Christoph Bergmann ◽  
Michael Endl ◽  
John B. Hearnshaw ◽  
Robert A. Wittenmyer ◽  
Duncan J. Wright
Keyword(s):  
Binary System ◽  
Radial Velocity ◽  
Binary Systems ◽  
Angular Separation ◽  
Radial Velocities ◽  
The Other ◽  
Cross Contamination ◽  
Star System ◽  
Spectroscopic Binary ◽  
Ongoing Project

AbstractThis work is part of an ongoing project which aims to detect terrestrial planets in our neighbouring star system α Centauri using the Doppler method. Owing to the small angular separation between the two components of the α Cen AB binary system, the observations will to some extent be contaminated with light coming from the other star. We are accurately determining the amount of contamination for every observation by measuring the relative strengths of the H-α and NaD lines. Furthermore, we have developed a modified version of a well-established Doppler code that is modelling the observations using two stellar templates simultaneously. With this method we can significantly reduce the scatter of the radial velocity (RV) measurements due to spectral cross-contamination and hence increase our chances of detecting the tiny signature caused by potential Earth-mass planets. After correcting for the contamination we achieve RV precision of ~2.5 m s−1 for a given night of observations. We have also applied this new Doppler code to four southern double-lined spectroscopic binary systems (HR159, HR913, HR7578 and HD181958) and have successfully recovered radial velocities for both components simultaneously.

scholarly journals First orbital elements for theλ Bootis spectroscopic binary systems HD 84948 and HD 171948

2002 ◽  
Vol 381 (3) ◽  
pp. 914-922 ◽  
Author(s):  
I. Kh. Iliev ◽  
E. Paunzen ◽  
I. S. Barzova ◽  
R. F. Griffin ◽  
I. Kamp ◽  
...  
Keyword(s):  
Binary Systems ◽  
Orbital Elements ◽  
Spectroscopic Binary

scholarly journals The CARMENES search for exoplanets around M dwarfs

2018 ◽  
Vol 619 ◽  
pp. A32 ◽  
Author(s):  
D. Baroch ◽  
J. C. Morales ◽  
I. Ribas ◽  
L. Tal-Or ◽  
M. Zechmeister ◽  
...  
Keyword(s):  
Binary Systems ◽  
Spectroscopic Binaries ◽  
M Dwarfs ◽  
Dwarf Stars ◽  
Double Line ◽  
Orbital Parameters ◽  
Rotation Periods ◽  
Spectroscopic Binary ◽  
M Dwarf Stars ◽  
M Dwarf

Context. The CARMENES spectrograph is surveying ∼300 M dwarf stars in search for exoplanets. Among the target stars, spectroscopic binary systems have been discovered, which can be used to measure fundamental properties of stars. Aims. Using spectroscopic observations, we determine the orbital and physical properties of nine new double-line spectroscopic binary systems by analysing their radial velocity curves. Methods. We use two-dimensional cross-correlation techniques to derive the radial velocities of the targets, which are then employed to determine the orbital properties. Photometric data from the literature are also analysed to search for possible eclipses and to measure stellar variability, which can yield rotation periods. Results. Out of the 342 stars selected for the CARMENES survey, 9 have been found to be double-line spectroscopic binaries, with periods ranging from 1.13 to ∼8000 days and orbits with eccentricities up to 0.54. We provide empirical orbital properties and minimum masses for the sample of spectroscopic binaries. Absolute masses are also estimated from mass-luminosity calibrations, ranging between ∼0.1 and ∼0.6 M⊙. Conclusions. These new binary systems increase the number of double-line M dwarf binary systems with known orbital parameters by 15%, and they have lower mass ratios on average.

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