- ID:
- ivo://CDS.VizieR/J/A+A/583/A85
- Title:
- Binaries in beta Pic moving group
- Short Name:
- J/A+A/583/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We look for common proper motion companions to stars of the nearby young {beta} Pictoris moving group. First, we compiled a list of 185 {beta} Pictoris members and candidate members from 35 representative works. Next, we used the Aladin and STILTS virtual observatory tools and the PPMXL proper motion and Washington Double Star catalogues to look for companion candidates. The resulting potential companions were subjects of a dedicated astro-photometric follow-up using public data from all-sky surveys. After discarding 67 sources by proper motion and 31 by colour-magnitude diagrams, we obtained a final list of 36 common proper motion systems. The binding energy of two of them is perhaps too small to be considered physically bound. Of the 36 pairs and multiple systems, eight are new, 16 have only one stellar component previously classified as a {beta} Pictoris member, and three have secondaries at or below the hydrogen-burning limit. Sixteen stars are reported here for the first time as moving group members. The unexpected large number of high-order multiple systems, 12 triples and two quadruples among 36 systems, may suggest a biased list of members towards close binaries or an increment of the high-order-multiple fraction for very wide systems.
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1822. Binaries in NGC 3201
- ID:
- ivo://CDS.VizieR/J/ApJS/90/83
- Title:
- Binaries in NGC 3201
- Short Name:
- J/ApJS/90/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present BV CCD and APM photometry, accurate astrometry and 1859 radial velocities for 1318 stars within ~36deg of the Galactic globular cluster NGC 3201. The field and cluster populations separate unambiguously in two distinct samples since the systemic radial velocity of NGC 3201 is 494.2km/s. After removal of the 19 known NGC 3201 photometric variables in our sample, we have a database of 930 radial velocities for 420 member giants (276 of which have multiple velocity measurements) with which to identify spectroscopic binaries on the basis of radial velocity variations. The mean time span of the observations is 1.7yr, with coverage up to ~6yr for our best-studied stars. Monte Carlo simulations of the observed velocity variations have provided _upper_limits_ to the cluster binary fraction (for binaries with 0.1<=P<=5-10yr and mass ratios in the range 0.1-1) of 0.06-0.10 (circular orbits) and 0.15-0.18 (eccentric orbits). These results suggest an incidence of binarism for NGC 3201 consistent with the corresponding incidence among nearby solar-type stars having similar periods and mass ratios (0.04-0.08) and that for a small sample of other globular clusters (0.05-0.12) studied by Hut et al. (1992PASP..104..981H). The detailed analysis of the cluster dynamics, based on the data given here, are presented by Cote et al. (1995ApJ...454..788C).
- ID:
- ivo://CDS.VizieR/J/ApJ/521/682
- Title:
- Binaries in the Praesepe and Coma clusters
- Short Name:
- J/ApJ/521/682
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This completes a study of the evolution of binary systems in five open clusters of various ages. Among 21 stars observed in Praesepe, eight are found or confirmed to be spectroscopic binaries and orbital elements are derived, while one more shows long-term binary motion. Among 18 stars observed in the Coma Berenices cluster, five are found or confirmed to be spectroscopic binaries and orbital elements are derived, while a sixth has tentative elements.
- ID:
- ivo://CDS.VizieR/J/other/PNAOJ/2.561
- Title:
- Binaries speckle observations. IV.
- Short Name:
- J/other/PNAOJ/2.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the fourth paper of this series giving results of speckle observations for 22 visual and 161 spectroscopic binaries. The observation was carried out by using the 212 cm telescope of San Pedro Martir Observatory in Mexico at 7 nights from July 20 to July 26, 1991. We obtained fringes in power spectra of i 19 visual and 11 spectroscopic binaries (6 newly resolved ones) with angular separation larger than 0.06". We introduced a new ICCD TV camera in this observation, and were able to achieve the diffraction-limit resolution of the 212 cm telescope.
- ID:
- ivo://CDS.VizieR/J/MNRAS/479/1332
- Title:
- Binaries with F, G or K primaries and M dwarfs
- Short Name:
- J/MNRAS/479/1332
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigated almost 500 stars distributed among 193 binary or multiple systems made of late-F, G-, or early-K primaries and late-K or M dwarf companion candidates. For all of them, we compiled or measured coordinates, J-band magnitudes, spectral types, distances, and proper motions. With these data, we established a sample of 192 physically bound systems. In parallel, we carried out observations with HERMES/Mercator and obtained high-resolution spectra for the 192 primaries and five secondaries. We used these spectra and the automatic STEPAR code for deriving precise stellar atmospheric parameters: Teff, logg, {xi}, and chemical abundances for 13 atomic species, including [Fe/H]. After computing Galactocentric space velocities for all the primary stars, we performed a kinematic analysis and classified them in different Galactic populations and stellar kinematic groups of very different ages, which match our own metallicity determinations and isochronal age estimations. In particular, we identified three systems in the halo and 33 systems in the young Local Association, Ursa Major and Castor moving groups, and IC 2391 and Hyades Superclusters. We finally studied the exoplanet-metallicity relation in our 193 primaries and made a list 13 M-dwarf companions with very high metallicity that can be the targets of new dedicated exoplanet surveys. All in all, our dataset will be of great help for future works on the accurate determination of metallicity of M dwarfs.
- ID:
- ivo://CDS.VizieR/J/A+A/379/162
- Title:
- Binaries with post-T Tauri secondaries
- Short Name:
- J/A+A/379/162
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File table2 contains the values of the color indices: (b-y), m1, c1, H{beta}, from the Stroemgren photometry and the observational errors on these indices as given by the Hauck and Mermiliod (1998, Cat. <II/215>). The values of Teff and logg are obtained from the Moon & Dworetsky (1985MNRAS.217..305M) calibration to which we have implemented the corrections by Castelli (1991A&A...251..106C). The errors on the parameters Teff and logg, as explained in section 3.3, are the consequence of the observational error on the photometric indices; SigmaTeff is the total error, on Teff, computed as explained in section 3.3. File table5 contains the values of the parallax, the error on the parallax, the Teff and the luminosity for the early-type star and late type star of each visual binary system. The errors on the Teff and on the luminosity are taken into account to compute for each of these parameters its minimum and maximum value. File table7 gives the values of the ages and masses computed for the early-type stars from the Schaller et al. (1993, Cat. <J/A+AS/96/269>) isochrones and Meynet at al. (1993A&AS...98..477M) models and from the Girardi et al. (2000, Cat. <J/A+AS/141/371>) models. The errors on the Teff and the luminosity are used to compute the minimum and the maximum values for the age and the mass. The last two columns concern only the primary stars with a Teff greater than 15000K for which we also compute the age and the mass using as Teff value: (Teff-500K); 500K corresponds to the systematic shift between Teff derived by using different photometric system (see Sect. 3.3). File table9 gives the values of the ages and masses computed for the late-type components from the isochrones and evolutionary tracks by D'Antona et al. (1998, web page, http://www.mporzio.astro.it/~dantona/ ) Palla and Stahler (1999ApJ...525..772P), Siess et al. (2000A&A...358..593S) and Tout et al. (1999MNRAS.310..360T). When possible, the minimum and the maximum values of these parameters are given by taking into account the errors on the Teff and on the luminosity.
- ID:
- ivo://CDS.VizieR/J/AJ/134/26
- Title:
- Binaries with white dwarf in 2MASS
- Short Name:
- J/AJ/134/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the culmination of our near-infrared survey of the optically spectroscopically identified white dwarf stars from the McCook and Sion (1999ApJS..121....1M, see Cat. <III/235>) catalog, conducted using photometric data from the Two Micron All Sky Survey final All Sky Data Release. The color selection technique, which identifies candidate binaries containing a white dwarf and a low-mass stellar (or substellar) companion via their distinctive locus in the near-infrared color-color diagram, is demonstrated to be simple to apply and to yield candidates with a high rate of subsequent confirmation. We recover 105 confirmed binaries, and identify 27 firm candidates (19 of which are new to this work) and 21 tentative candidates (17 of which are new to this work) from the 2MASS data.
- ID:
- ivo://CDS.VizieR/J/A+A/315/384
- Title:
- Binarity among B-stars in NGC 6231
- Short Name:
- J/A+A/315/384
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have measured radial velocities for 53 B-type stars, between B1 and B9, in the young open cluster NGC 6231 through a cross-correlation technique with synthetic spectra. Two measurements for 36 stars of the sample were obtained with a time separation of about two years. We derived a minimum binary fraction of 52% in the considered population. The velocity determination precisions were simulated and we analysed their dependence upon the S/N ratios of the spectra and upon the stellar rotational velocities. We discuss the selection of the templates for the correlation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/428/2118
- Title:
- Binarity in planetary nebula central stars
- Short Name:
- J/MNRAS/428/2118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We still do not know what causes aspherical planetary nebula (PN) morphologies. A plausible hypothesis is that they are due to the presence of a close stellar or substellar companion. So far, only ~40 binary central stars of PN have been detected, almost all of them with such short periods that their binarity is revealed by photometric variability. Here we have endeavoured to discover binary central stars at any separation, thus determining the unbiased binary fraction of central stars of PN. This number, when compared to the binary fraction of the presumed parent population, can give a first handle on the origin of PN. By detecting the central stars in the I band we have searched for cool companions.
- ID:
- ivo://CDS.VizieR/J/A+A/623/A72
- Title:
- Binarity of Hipparcos stars from Gaia pm anomaly
- Short Name:
- J/A+A/623/A72
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The census of stellar and substellar companions of nearby stars is largely incomplete, in particular towards the low mass brown dwarf and long-period exoplanets. It is however of fundamental importance to understand the stellar and planetary formation and evolution mechanisms. Nearby stars are particularly favorable targets for high precision astrometry. We aim at characterizing the presence of physical companions of stellar and substellar mass in orbit around nearby stars. Orbiting secondary bodies influence the proper motion of their parent star through their gravitational reflex motion. Using the Hipparcos and Gaia DR2 catalogs, we determine the long-term proper motion of the stars common to these two catalogs. We then search for a proper motion anomaly (PMa) between the long-term proper motion vector and the Gaia DR2 (or Hipparcos) measurements, indicative of the presence of a perturbing secondary object. We focus our analysis on the 6741 nearby stars located within 50pc, and we also present a catalog of the PMa for >99 percent of the stars of the full Hipparcos catalog. A fraction of 30 percent of the studied stars presents a PMa at a level of more than 3 sigma. The PMa allows us to detect orbiting companions, or set stringent limits to their presence. We present a few illustrations of the PMa analysis to interesting targets. We set upper limits of 0.1-0.3MJ to potential planets orbiting Proxima between 1 and 10au (P_orb_=3 to 100 years). We confirm that Proxima is gravitationally bound to alpha Cen. We recover the masses of the known companions of epsilon Eri, epsilon Ind, Ross 614 and beta Pic. We also detect the signature of a possible planet of a few jovian masses orbiting tau Ceti. Based on only 22 months of Gaia data, the DR2 has limitations, but its combination with the Hipparcos catalog and the very high accuracy of the derived PMa already enables to set valuable constraints on the binarity of nearby objects. The detection of tangential velocity anomalies at a median accuracy of sigma({Delta}v_T_)=1.0m/s per parsec of distance is already possible with the Gaia DR2. This type of analysis opens the possibility to identify long period orbital companions otherwise inaccessible. The complementarity of Gaia (for long orbital periods), radial velocity and transit techniques (for short periods) already appears as remarkably powerful.
