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Spectroscopic Binaries (spectroscopic + binary)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Physical parameters of the O6.5V+B1V eclipsing binary system LS 1135

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2006
E. Fernández Lajús
ABSTRACT The ,All Sky Automated Survey' (ASAS) photometric observations of LS 1135, an O-type single-lined binary (SB1) system with an orbital period of 2.7 d, show that the system is also eclipsing performing a numerical model of this binary based on the Wilson,Devinney method. We obtained an orbital inclination . With this value of the inclination, we deduced masses M1, 30 ± 1 M, and M2, 9 ± 1 M,, and radii R1, 12 ± 1 R, and R2, 5 ± 1 R, for primary and secondary components, respectively. Both the components are well inside their respective Roche lobes. Fixing the Teff of the primary to the value corresponding to its spectral type (O6.5V), the Teff obtained for the secondary component corresponds approximately to a spectral type of B1V. The mass ratio M2/M1, 0.3 is among the lowest known values for spectroscopic binaries with O-type components. [source]

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

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2003
J.-M. Carquillat
ABSTRACT 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. [source]

Spectroscopic orbits of potential interferometric binaries

ASTRONOMISCHE NACHRICHTEN, Issue 6-8 2004
F. C. Fekel
Abstract We are obtaining high-resolution, red-wavelength spectra at McDonald and Kitt Peak National Observatory to improve the orbits of known spectroscopic binaries that are potential targets for ground-based optical interferometers. The combination of such observations will produce three-dimensional orbits from which very accurate masses and orbital parallaxes can be obtained for double-lined systems. This spectroscopic program will be expanded and placed on the menu of the 2 meter Automatic Spectroscopic Telescope of Tennessee State University once it commences routine operation. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

HD 1: The number-one star in the sky,

ASTRONOMISCHE NACHRICHTEN, Issue 4 2010
K.G. Strassmeier
Abstract We present the first ever study of the bright star HD 1. The star was chosen arbitrarily just because of its outstanding Henry Draper number. Surprisingly, almost nothing is known about this bright 7.m4 star. Our observations were performed as part of the commissioning of the robotic telescope facility STELLA and its fiber-fed high-resolution optical echelle spectrograph SES in the years 2007,2010. We found long-term radial velocity variations with a full amplitude of 9 km s,1 with an average velocity of ,29.8 km s,1 and suggest the star to be a hitherto unknown single-lined spectroscopic binary. A preliminary orbit with a period of 6.2 years (2279±69 days) and an eccentricity of 0.50±0.01 is given. Its rms uncertainty is just 73 m s,1. HD 1 appears to be a G9-K0 giant of luminosity class IIIa with Teff = 4850±100 K, logg = 2.0±0.2, L , 155 L,, a mass of 3.0±0.3 M,, a radius of 17.7 R,, and an age of ,350 Myr. A relative abundance analysis led to a metallicity of [Fe/H] = ,0.12 ± 0.09. The , -element silicon may indicate an overabundance of +0.13 though. The low strengths of some s-process lines and a lower limit for the 12C/13C isotope ratio of ,16 indicate that HD 1 is on the first ascend of the RGB. The absorption spectral lines appear rotationally broadened with a v sin i of 5.5±1.2 km s,1 but no chromospheric activity is evident. We also present photometric monitoring BV (RI)C data taken in parallel with STELLA. The star is likely a small-amplitude (<10 mmag) photometric variable although no periodicity was found (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]