- ID:
- ivo://CDS.VizieR/J/A+A/394/151
- Title:
- Multiplicity among chemically peculiar stars II
- Short Name:
- J/A+A/394/151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new orbits for sixteen Ap spectroscopic binaries, four of which might in fact be Am stars, and give their orbital elements. Four of them are SB2 systems: HD 5550, HD 22128, HD 56495 and HD 98088. The twelve other stars are : HD 9996, HD 12288, HD 40711, HD 54908, HD 65339, HD 73709, HD 105680, HD 138426, HD 184471, HD 188854, HD 200405 and HD 216533. Rough estimates of the individual masses of the components of HD 65339 (53 Cam) are given, combining our radial velocities with the results of speckle interferometry and with Hipparcos parallaxes. Considering the mass functions of 74 spectroscopic binaries from this work and from the literature, we conclude that the distribution of the mass ratio is the same for cool Ap stars as for normal G dwarfs. Therefore, the only differences between binaries with normal stars and those hosting an Ap star lie in the period distribution: except for the case of HD 200405, all orbital periods are longer than (or equal to) 3 days. A consequence of this peculiar distribution is a deficit of null eccentricities. There is no indication that the secondary has a special nature, like e.g. a white dwarf.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/441/2316
- Title:
- 10 nearby solar-type dwarfs RV curves
- Short Name:
- J/MNRAS/441/2316
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Several nearby solar-type dwarfs with variable radial velocity were monitored to find their spectroscopic orbits. Orbital elements of HIP 179, 1989, 2981, 5276, 6439, 11218, 21443, 96434 are determined, as well as tentative orbits for HIP 28678 and 41214. We discuss each of those objects. Three of the four double-lined binaries are twins with nearly equal components. All four orbits with periods shorter than 10d are circular, the remaining orbits are eccentric.
- ID:
- ivo://CDS.VizieR/J/AJ/144/7
- Title:
- Near-IR imaging of Hipparcos astrometric binaries
- Short Name:
- J/AJ/144/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A subset of 51 Hipparcos astrometric binaries among FG dwarfs within 67pc has been surveyed with the Near-Infrared Coronagraphic Imager adaptive optics system at Gemini-S, directly resolving for the first time 17 subarcsecond companions and 7 wider ones. Using these data together with published speckle interferometry of 57 stars, we compare the statistics of resolved astrometric companions with those of a simulated binary population. The fraction of resolved companions is slightly lower than expected from binary statistics. About 10% of astrometric companions could be "dark" (white dwarfs and close pairs of late M-dwarfs). To our surprise, several binaries are found with companions too wide to explain the acceleration. Re-analysis of selected intermediate astrometric data shows that some acceleration solutions in the original Hipparcos catalog are spurious.
- ID:
- ivo://CDS.VizieR/J/A+A/375/130
- Title:
- New PMS spectroscopic binaries in Orion
- Short Name:
- J/A+A/375/130
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 2 contains the heliocentric radial velocity data versus Heliocentric Julian Day for six X-ray selected double-lined spectroscopic binaries in Orion. Of these, the four systems RXJ 0529.4+0041, RXJ 0530.7-0434, RXJ 0532.1-0732, and RXJ 0541.4-0324 are pre-main sequence systems. Table 3 contains the radial velocity data for the third components of the spectroscopic systems RXJ 0441.0-0839, RXJ 0529.4+0041, and RXJ 0532.1-0732
- ID:
- ivo://CDS.VizieR/J/ApJ/629/507
- Title:
- Observed orbital eccentricities for 391 binaries
- Short Name:
- J/ApJ/629/507
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For 391 spectroscopic and visual binaries with known orbital elements and having B0-F0 IV or V primaries, we collected the derived eccentricities. As has been found by others, those binaries with periods of a few days have been circularized. However, those with periods up to about 1000 or more days show reduced eccentricities that asymptotically approach a mean value of 0.5 for the longest periods. For those binaries with periods greater than 1000 days their distribution of eccentricities is flat from 0 to nearly 1, indicating that in the formation of binaries there is no preferential eccentricity. The binaries with intermediate periods (10-100 days) lack highly eccentric orbits.
- ID:
- ivo://CDS.VizieR/J/A+A/598/A84
- Title:
- OB-type spectroscopic binaries
- Short Name:
- J/A+A/598/A84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Massive binaries play a crucial role in the Universe. Knowing the distributions of their orbital parameters is important for a wide range of topics from stellar feedback to binary evolution channels and from the distribution of supernova types to gravitational wave progenitors, yet no direct measurements exist outside the Milky Way. The Tarantula Massive Binary Monitoring project was designed to help fill this gap by obtaining multi-epoch radial velocity (RV) monitoring of 102 massive binaries in the 30 Doradus region. In this paper we analyze 32 FLAMES/GIRAFFE observations of 93 O- and 7 B-type binaries. We performed a Fourier analysis and obtained orbital solutions for 82 systems: 51 single-lined (SB1) and 31 double-lined (SB2) spectroscopic binaries. Results. Overall, the binary fraction and orbital properties across the 30 Doradus region are found to be similar to existing Galactic samples. This indicates that within these domains environmental effects are of second order in shaping the properties of massive binary systems. A small difference is found in the distribution of orbital periods, which is slightly flatter (in log space) in 30 Doradus than in the Galaxy, although this may be compatible within error estimates and differences in the fitting methodology. Also, orbital periods in 30 Doradus can be as short as 1.1d, somewhat shorter than seen in Galactic samples. Equal mass binaries (q>0.95) in 30 Doradus are all found outside NGC 2070, the central association that surrounds R136a, the very young and massive cluster at 30 Doradus's core. Most of the differences, albeit small, are compatible with expectations from binary evolution. One outstanding exception, however, is the fact that earlier spectral types (O2-O7) tend to have shorter orbital periods than later spectral types (O9.2-O9.7). Our results point to a relative universality of the incidence rate of massive binaries and their orbital properties in the metallicity range from solar (Z_{sun}_) to about half solar. This provides the first direct constraints on massive binary properties in massive star-forming galaxies at the Universe's peak of star formation at redshifts z~1 to 2 which are estimated to have Z~0.5 Z_{sun}_.
- ID:
- ivo://CDS.VizieR/J/A+A/473/829
- Title:
- Orbital elements of 156 spectroscopic binaries
- Short Name:
- J/A+A/473/829
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a comprehensive, long-term monitoring programme aiming to improve our knowledge of such binary systems. We monitored the radial velocities of 1309 red giants in 187 open clusters with the Coravel spectrometers for 20 years, with a typical accuracy of 0.4km/s per observation. In total, 289 spectroscopic binaries were detected in the sample. We present first orbits for 67 systems and improved elements for another 64 previously published orbits, based on additional observations. For completeness, 25 published orbits are listed as well. The orbits are based on a total of 4039 observations, an average of 26 per system. Orbital periods range from 41.5 to 14722-days (40yrs), eccentricities from 0.00 to 0.81. The remaining systems have too long periods and/or inadequate phase coverage for an orbit determination at this time or too few observations.
- ID:
- ivo://CDS.VizieR/J/A+A/562/A95
- Title:
- Orbital solutions of eight close sdB binaries
- Short Name:
- J/A+A/562/A95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims at finding hot subdwarf stars (sdBs) with massive compact companions such as white dwarfs, neutron stars, or stellar-mass black holes. In a supplementary programme we obtained time-resolved spectroscopy of known hot subdwarf binary candidates. Here we present orbital solutions of eight close sdB binaries with orbital periods ranging from 0.1 to 10 days, which allow us to derive lower limits on the masses of their companions. Additionally, a dedicated photometric follow-up campaign was conducted to obtain light curves of the reflection-effect binary HS 2043+0615. We are able to constrain the most likely nature of the companions in all cases but one, making use of information derived from photometry and spectroscopy. Four sdBs have white dwarf companions, while another three are orbited by low-mass main sequence stars of spectral type M.
- 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.
