Contribution to the search for binaries among Am stars – V. Orbital elements of eight short-period spectroscopic binaries

We present the results of a radial-velocity study of eight Am stars (HD 341, 55822, 61250, 67317, 93991, 162950, 224890 and 225137) observed at Observatoire de Haute-Provence with the CORAVEL instrument. We find that these systems are single-line spectroscopic binaries whose orbital elements are determined for the first time.     

Contribution to the study of composite spectra: XI. Orbital elements of some faint systems

We present the results of a radial‐velocity study of nine new faint SB1 spectroscopic binaries with composite spectra: HD 137975‐6, 177984, HDE 226489, 231613‐4, 255387‐8, 256138‐9, 264997‐8, 276787 and 293041‐2. The observations were made at Haute‐Provence and Cambridge observatories with CORAVEL instruments between 1982 and 2006. From the radial‐velocity measurements of the cool components, we derive the orbital elements of those spectroscopic binaries for the first time. Using all the available data, we propose a model for each system that describes the nature of the individual components, with an estimation of the angular separation and orbital inclination. Finally we discuss the rotation–revolution synchronism of the cool components. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Contribution to the study of composite spectra: XII. Spectroscopic orbits of eight southern stars

We present the results of a radial‐velocity study of eight southern SB1 spectroscopic binaries with composite spectra: HD 34318‐9, HD 47579‐80, HD 70442‐3, HD 74946‐7, HD 102171‐2, HD 120901‐2, HD 168701‐2, and HD 174191‐2. The observations were made at Haute‐Provence observatory with the CORAVEL instrument between 1982 and 2006. From the radial‐velocity measurements of the cool components, we derive the orbital elements of those spectroscopic binaries. Using all the available data, we obtain an estimation of the orbital inclination and the angular separation of the two components. Finally we discuss the rotation‐revolution synchronism of the cool components. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Contribution to the study of F‐G‐K‐M binaries: XII. Orbital elements of seven new spectroscopic binaries

The orbital elements of seven single‐lined spectroscopic binaries, HD 31855, HD 59643, HD 60092, HD 133189, HD 162262, HD 203522, BD +43° 1331 are presented. They are obtained from observations made with two photoelectric spectrometers of CORAVEL type, the first located at the Observatoire de Haute‐Provence and the second at the Cambridge Observatories. From those orbital elements and other data available in the literature, we deduce some information about the unseen companions and their separations with respect to the primaries. We then discuss the rotation‐revolution synchronism and conclude that some of those stars have probably reached the state of (pseudo‐)synchronism. Finally we give a synopsis of the results obtained in this series of papers. Our radial velocity monitoring of more than three decades has allowed us to derive accurate orbital elements of 35 spectroscopic binaries, with a cool primary star of type F‐G‐K‐M. The corresponding range of periods varies from a few days to more than 10 years. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Contribution to the study of F‐G‐K‐M binaries. X. HD 54901, HD 120544 and HD 123280, three nearby F‐type spectroscopic binaries

The orbital elements of HD 54901, HD 120544 and HD 123280, three nearby F‐type spectroscopic binaries, are presented. They are based on observations made between 1982 and 2004 with the CORAVEL instrument of Observatoire de Haute‐Provence. Physical parameters are derived for the two components of HD 54901 (SB2) and for the primaries of HD 120544 and HD 123280. The rotation‐revolution synchronism of the detected components is investigated. Pseudosynchronism is very likely achieved by the F7 V secondary component of HD 54901, whereas the F2/3 IV primary has not yet reached this stage. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Contribution to the search for binaries among Am stars – VIII. New spectroscopic orbits of eight systems and statistical study of a sample of 91 Am stars

Red clump giant (RCG) stars can be used as distance indicators to trace the mass distribution of the Galactic bar. We use RCG stars from 44 bulge fields from the OGLE-II microlensing collaboration data base to constrain analytic triaxial models for the Galactic bar. We find the bar major-axis is oriented at an angle of 24°–27° to the Sun–Galactic Centre line-of-sight. The ratio of semimajor and semiminor bar axis scalelengths in the Galactic plane   x ₀, y ₀  , and vertical bar scalelength z ₀, is   x ₀ :  y ₀ :  z ₀= 10 : 3.5 : 2.6  , suggesting a slightly more prolate bar structure than the working model of Gerhard which gives the scalelength ratios as   x ₀ :  y ₀ :  z ₀= 10 : 4 : 3  .     

Contribution to the study of binaries with spectral types F,G, K,and M – XI. Orbital elements of three red‐giant spectroscopic binaries: HR 1304, HR 1908, and HD 126947

The orbital elements of three red‐giant single‐lined spectroscopic binaries, HR 1304, HR 1908 and HD 126947, are presented. They are obtained from observations made with two photoelectric spectrometers of CORAVEL type, the first located at the Observatoire de Haute‐Provence and the second at the Cambridge Observatories. HR 1304 and HR 1908 are known to be chromospherically active stars and to have high spatial velocities; HD 126947 is an intrinsic variable newly detected by Hipparcos. The three systems have long orbital periods: 1.9, 3.2 and 7.7 yr for HR 1304, HR 1908 and HD 126947, respectively. From the orbital elements that we determined and other data available in the literature, we deduce some information about the unseen companions and their separations with respect to the primaries. Finally we discuss the rotation–revolution synchronism and conclude that one star, HR 1908, may have reached the state of pseudo‐synchronism, despite of its long orbital period. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Surface abundances of light elements for a large sample of early B-type stars – II. Basic parameters of 107 stars

Effective temperatures T _eff, surface gravities log  g and interstellar extinctions A _V are found for 107 B stars. Distances d of the stars, which are based on the derived T _eff, log  g and A _V values, show good agreement with those obtained from the Hipparcos parallaxes. Comparing the T _eff and log  g values with evolutionary computations, we infer masses, radii, luminosities, ages and relative ages of the stars. Empirical relations between the T _eff and log  g parameters, on the one hand, and the photometric indices Q , [ c ₁] and β , on the other hand, are constructed; these relations give a fast method for the T _eff and log  g estimation of early and medium B stars. Inclusion of the infrared J , H and K colours into the T _eff, log  g and A _V determination shows that (i) the T _eff and log  g parameters are altered only slightly; (ii) the A _V value is rather sensitive to these colours, so an accuracy better than 0.05 mag in the JHK data is necessary for precise A _V evaluation.     

A new method of determining the inclination angle in interacting binaries

We describe a method of determining the system parameters in non-eclipsing interacting binaries. We find that the extent to which an observer sees the shape of the Roche lobe of the secondary star governs the amount of distortion of the absorption-line profiles. The width and degree of asymmetry of the phase-resolved absorption-line profiles show a characteristic shape, which depends primarily on the binary inclination and gravity darkening exponent. We show that, in principle, by obtaining high spectral and time resolution spectra of quiescent cataclysmic variables or low-mass X-ray binaries in which the mass-losing star is visible, fitting the shape of absorption-line profiles will allow one to determine not only the mass function of the binary, but also the binary inclination and hence the mass of the binary components.