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- ID:
- ivo://CDS.VizieR/J/ApJ/681/562
- Title:
- Orbits of 5 Cet and AX Mon
- Short Name:
- J/ApJ/681/562
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I discuss the effect of physical distortion on the velocities of close binary components and how we may use the resulting distortion of velocity curves to constrain some properties of binary systems, such as inclination and mass ratio. Precise new velocities for 5 Cet convincingly detect these distortions with their theoretically predicted phase dependence. We can even use such distortions of velocity curves to test Lucy's theory of convective gravity darkening. The observed distortions for TT Hya and 5 Cet require the contact components of those systems to be gravity darkened, probably somewhat more than predicted by Lucy's theory, but clearly not as much as expected for a radiative star. These results imply there is no credible evidence for eccentric orbits in binaries with contact components. I also present some speculative analyses of the observed properties of a binary encased in a nonrotating common envelope, if such an object could actually exist, and discuss how the limb darkening of some recently calculated model atmospheres for giant stars may bias my results for velocity-curve distortions, as well as other results from a wide range of analyses of binary stars.
- ID:
- ivo://CDS.VizieR/J/AJ/156/194
- Title:
- Orbits of double-lined pairs in multiple stars
- Short Name:
- J/AJ/156/194
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectroscopic orbits are computed for inner pairs in nine hierarchical multiple systems (HIP 19639, 60845, 75663, 76816, 78163, 78416, 80448, 84789, and HD 105080) and for one simple binary HIP 61840. All subsystems are double-lined, and their periods range from 2.27 to 30.4 days. Five spectroscopic binaries are twins with equal masses. Each hierarchical system is discussed individually, providing estimates of outer periods, masses, orbital inclination, and axial rotation. For systems with three resolved visual components (HIP 60845 and 80448), the outer and inner visual orbits are determined, complementing the description of their architecture. The radial velocities of HIP 75663A, 76816B, and 78163B are found to be variable with long periods, implying that these hierarchies are 2 + 2 quadruples. The period-eccentricity relation for spectroscopic subsystems is discussed.
- ID:
- ivo://CDS.VizieR/J/AJ/146/129
- Title:
- Orbits of 4 double-lined spectroscopic binaries
- Short Name:
- J/AJ/146/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Improved orbital elements for four A-star double-lined spectroscopic binaries have been determined with numerous new radial velocities. Three of the four systems, HR 1528, 2 Sge, and 18 Vul, have moderately short orbital periods of 7.05, 7.39, and 9.31 days, respectively, and also have circular or nearly circular orbits. Only HR 6993 with a period of 14.68 days has a significantly eccentric orbit. The close visual companion of 2 Sge has been detected spectroscopically, and its velocity measured. The orbital dimensions (a_1_sini and a_2_sini) and minimum masses (m_1_sin^3^i and m_2_ sin^3^i) of the short-period binary components all have accuracies of 0.5% or better. We determine basic properties of the individual stars and compare them with solar-abundance evolutionary tracks to estimate their masses. Half of the eight components may be synchronously or pseudosynchronously rotating.
- ID:
- ivo://CDS.VizieR/J/AJ/152/11
- Title:
- Orbits of four triple stars
- Short Name:
- J/AJ/152/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Each of the nearby triple systems HIP 7601, 13498, 23824, and 113597 (HD 10800, 18198, 35877, 217379) consist of solar-type dwarfs with comparable masses, where all three components are resolved spectrally, while the outer pairs are resolved both visually and spectrally. These stars are relatively young (between 100 and 600Myr) and chromospherically active (X-ray sources), although they rotate slowly. I determine the spectroscopic orbits of the inner subsystems (periods 19.4, 14.1, 5.6, 20.3days) and the orbits of the outer systems (periods 1.75, 51, 27, 500years, respectively). For HIP 7601 and 13498, the combined spectro-interferometric outer orbits produce direct measurement of the masses of all of the components, allowing for a comparison with stellar models. The 6708{AA} lithium line is present and its strength is measured in each component individually by subtracting the contributions of the other components. The inner and outer orbits of HIP 7601 are nearly circular, likely co-planar, and have a modest period ratio of 1:33. This study contributes to the characterization of hierarchical multiplicity in the solar neighborhood and provides data for testing stellar evolutionary models and chronology.
1126. Orbits of 8 multiples
- ID:
- ivo://CDS.VizieR/J/A+AS/136/373
- Title:
- Orbits of 8 multiples
- Short Name:
- J/A+AS/136/373
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New close sub-systems are discovered in 8 visual late-type double stars. Elements of spectroscopic orbits (4 double-lined and 4 single-lined) are given for the components of quadruple systems ADS 1134 and 11163, for the components of triple systems ADS 455, 497, 5436, 8236, 10044, and for the primary of the optical pair ADS 9444. Magnitudes, colors, spectral types, masses of individual components are estimated by combining all available data with Hipparcos parallaxes. Among these stellar systems we note a subdwarf triple ADS 497, an old system with subgiant components ADS 10044, and a visual triple ADS 11163 with additional very low mass (possibly substellar) spectroscopic companion in a 4.6 day orbit. The astrometric orbit of ADS 8236B with a semimajor axis of 30 mas and a period of 4.6 yr may be recoverable from Hipparcos data.
- ID:
- ivo://CDS.VizieR/J/MNRAS/399/2146
- Title:
- Orbits of open clusters in the Galaxy
- Short Name:
- J/MNRAS/399/2146
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and analyse the kinematics and orbits for a sample of 488 open clusters (OCs) in the Galaxy. The velocity ellipsoid for our present sample is derived as ({sigma}(U),{sigma}(V),{sigma}(W)) = (28.7, 15.8, 11.0)km/s which represents a young thin-disc population. We also confirm that the velocity dispersions increase with the age of a cluster subsample. The orbits of OCs are calculated with three Galactic gravitational potential models. The errors of orbital parameters are also calculated considering the intrinsic variation of the orbital parameters and the effects of observational uncertainties. The observational uncertainties dominate the errors of derived orbital parameters. The vertical motions of clusters calculated using different Galactic disc models are rather different. The observed radial metallicity gradient of clusters is derived with a slope of b=-0.070+/-0.011dex/kpc. The radial metallicity gradient of clusters based on their apogalactic distances is also derived with a slope of b=-0.082+/-0.014dex/kpc. The distribution of derived orbital eccentricities for OCs is very similar to that derived for the field population of dwarfs and giants in the thin disc.
- ID:
- ivo://CDS.VizieR/J/AJ/124/1144
- Title:
- Orbits of 171 single-lined spectroscopic binaries
- Short Name:
- J/AJ/124/1144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 25,563 radial velocity measurements are reported for 1359 single-lined stars in the Carney-Latham sample of 1464 stars selected for high proper motion; for 171 of these, spectroscopic orbital solutions are derived. The radial velocities of nearly all of the 1464 stars defined in Paper XII (J/AJ/107/2240) have been monitored with the CfA Digital Speedometers (see Latham 1985, in IAU Colloq. 88, 21; and 1992, in IAU Colloq. 135, 110). Three nearly identical instruments have been used on the Multiple Mirror Telescope and 1.5 m Tillinghast Reflector at the F.L. Whipple Observatory atop Mount Hopkins, Arizona, and on the 1.5m Wyeth Reflector located at the Oak Ridge Observatory in the town of Harvard, Massachusetts. Echelle spectrographs have been used with photon counting intensified Reticon detectors to record about 45Angstroems of spectrum in a single order. Most of the spectra were centered near 5187Angstroems, but a significant number of the early spectra were centered near 5197Angstroems. The shift in central wavelength was adopted in order to include all three lines of the Mgb triplet, after it was fully appreciated that all the other lines in our spectral window became extremely weak for our most metal-poor stars. The spectral resolution is about 8.5km.s-1 for all our exposures, and the signal-to-noise ratios range from about 5 to 50 per resolution element.
- ID:
- ivo://CDS.VizieR/J/AJ/160/58
- Title:
- Orbits of spectro. binaries with CHARA Array. III.
- Short Name:
- J/AJ/160/58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the visual orbits of two long-period spectroscopic binary stars, HD8374 and HD24546, using interferometric observations acquired with the Center for High Angular Resolution Astronomy (CHARA) Array and the Palomar Testbed Interferometer. We also obtained new radial velocities from echelle spectra using the APO 3.5m and Fairborn 2.0 telescopes. By combining the visual and spectroscopic observations, we solve for the full, three-dimensional orbits and determine the stellar masses and distances to within 3% uncertainty. We then estimate the effective temperature and radius of each component star through Doppler tomography and spectral energy distribution analyses, in order to compare the observed stellar parameters to the predictions of stellar evolution models. For HD8374, we find masses of M1=1.636{+/-}0.050M{sun} and M2=1.587{+/-}0.049M{sun}, radii of R1=1.84{+/-}0.05R{sun} and R2=1.66{+/-}0.12R{sun}, temperatures of Teff_1_=7280{+/-}110K and Teff-2-=7280{+/-}120K, and an estimated age of 1.0Gyr. For HD24546, we find masses of M1=1.434{+/-}0.014M{sun} and M2=1.409{+/-}0.014M{sun}, radii of R_1_=1.67{+/-}0.06R{sun} and R_2_=1.60{+/-}0.10R{sun}, temperatures of Teff_1_=6790{+/-}120K and Teff_2_=6770{+/-}90K, and an estimated age of 1.4Gyr. HD24546 is therefore too old to be a member of the Hyades cluster, despite its physical proximity to the group.
- ID:
- ivo://CDS.VizieR/J/MNRAS/371/1159
- Title:
- Orbits of 30 spectroscopic binaries
- Short Name:
- J/MNRAS/371/1159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Three of the six southern Clube Areas that were mainly observed at the European Southern Observatory and whose principal results are given in Paper XVI (Griffin & Cornell 2006, Cat. <J/MNRAS/371/1140>) are marginally observable from Haute-Provence. Additional measurements obtained on several observing runs there enabled orbits to be determined (in most cases rather poorly, owing to the paucity of data) for 30 of the newly discovered spectroscopic-binary systems; they are presented in this paper. One object, HD 33978, seems to be of such significance that special efforts have been made, largely by Drs J. Andersen and H. Lindgren, to obtain additional radial-velocity measurements. That system is shown to be a double-lined binary with a period of only 10.67d despite one of its components being a late-type giant. The giant star has a projected rotational velocity of almost 40km/s; it could be expected to exhibit RS CVn-type photometric variations, which have not yet been observed, in addition to the 'ellipsoidal variation', discovered by Hipparcos, which occasioned its designation as VV Lep.
