- ID:
- ivo://CDS.VizieR/J/PAZh/41/896
- Title:
- Short- and long-term pm of close dwarfs
- Short Name:
- J/PAZh/41/896
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Motions of 1308 stars with large proper motions ({mu}>300mas/yr) up to 17 mag were investigated using the results of observations conducted with Pulkovo Normal Astrograph and images taken from data bases of sky surveys (DSS, SDSS DR12, WISE). Basic idea of search of double stars with this material is a comparison between long-term proper motion (POSS2-POSS1, epoch difference is about 50yr) and short-term proper motion (2MASS, SDSS, WISE, Pulkovo, epoch difference is about 10yr). Star is classified as delta-mu-binary candidate in the case of statistically significant difference of short-term and long-term proper motions. This condition is realised for 121 stars of our target list. Additional evidence of duplicity was obtained with comparison of our proper motions with data of several parallax determination programs. Analysis of accurate SDSS photometric values of our stars allows us to conclude that four stars (J0656+3827, J0838+3940, J1229+5332, J2330+4639) are probably binary systems which consist of wite dwarf + M-dwarf.
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Search Results
- ID:
- ivo://CDS.VizieR/I/264
- Title:
- Sixth Catalogue of Fundamental Stars (FK6)
- Short Name:
- I/264
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The FK6 is a suitable combination of the results of the HIPPARCOS (Cat. <I/239>) astrometry satellite with ground-based data, measured over more than two centuries. The FK6 gives other solutions than the classical `single-star mode' (SI mode), which take into account the fact that hidden astrometric binaries among `apparently single-stars' introduce sizable `cosmic errors' into the quasi-instantaneously measured HIPPARCOS proper motions and positions. The FK6 gives in addition to the SI mode the `long-term prediction (LTP) mode' and the `short-term prediction (STP) mode'. These LTP and STP modes are on average the most precise solutions for apparently single stars, depending on the epoch difference with respect to the HIPPARCOS epoch of about 1991. The FK6(I) results from the combination of FK5(I) (Cat. <I/149>) with Hipparcos results. Among its 878 stars, it contains 340 objects classified as `astrometrically excellent stars', most suited for high-precision astrometry. The typical mean error of an FK6(I) proper motion is 0.35 mas/year in the single-star mode (about two times better than Hipparcos), and 0.50 mas/year in the long-term prediction mode (about four times better than Hipparcos). The FK6(III) results from the combination of stars from FK5 extension (Cat. <I/175>) with Hipparcos. Among its 3272 stars, it contains 1928 objects classified as `astrometrically excellent stars'. The typical mean error of an FK6(III) proper motion is 0.59 mas/year in the single-star mode, and 0.93 mas/year in the long-term prediction mode.
- ID:
- ivo://CDS.VizieR/V/95
- Title:
- SKY2000 - Master Star Catalog
- Short Name:
- V/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The SKYMAP Star Catalog System consists of a Master Catalog stellar database and a collection of utility software designed to create and maintain the database and to generate derivative mission star catalogs (run catalogs). It contains an extensive compilation of information on almost 300000 stars.
634. SLoWPoKES catalog
- ID:
- ivo://CDS.VizieR/J/AJ/139/2566
- Title:
- SLoWPoKES catalog
- Short Name:
- J/AJ/139/2566
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Sloan Low-mass Wide Pairs of Kinematically Equivalent Stars (SLoWPoKES), a catalog of 1342 very-wide (projected separation >~500AU), low-mass (at least one mid-K to mid-M dwarf component) common proper motion pairs identified from astrometry, photometry, and proper motions in the Sloan Digital Sky Survey. A Monte Carlo-based Galactic model is constructed to assess the probability of chance alignment for each pair; only pairs with a probability of chance alignment <=0.05 are included in the catalog.
- ID:
- ivo://CDS.VizieR/J/AJ/143/67
- Title:
- SLoWPoKES. II. Properties of wide, low-mass binaries
- Short Name:
- J/AJ/143/67
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results from spectroscopic observations of 113 ultra-wide, low-mass binary systems, largely composed of M0-M3 dwarfs, from the SLoWPoKES catalog of common proper motion pairs identified in the Sloan Digital Sky Survey (Dhital et al., 2010, Cat. J/AJ/139/2566). Radial velocities of each binary member were used to confirm that they are comoving and, consequently, to further validate the high fidelity of the SLoWPoKES catalog. Ten stars appear to be spectroscopic binaries based on broad or split spectral features, supporting previous findings that wide binaries are likely to be hierarchical systems. We measured the H{alpha} equivalent width of the stars in our sample and found that components of 81% of the observed pairs have similar H{alpha} levels. The difference in H{alpha} equivalent width among components with similar masses was smaller than the range of H{alpha} variability for individual objects. We confirm that the Lepine et al. (2007ApJ...669.1235L) {zeta}-index traces iso-metallicity loci for most of our sample of M dwarfs. However, we find a small systematic bias in {zeta}, especially in the early-type M dwarfs. We use our sample to recalibrate the definition of {zeta}. While representing a small change in the definition, the new {zeta} is a significantly better predictor of iso-metallicity for the higher-mass M dwarfs.
636. SOAR TESS survey. I.
- ID:
- ivo://CDS.VizieR/J/AJ/159/19
- Title:
- SOAR TESS survey. I.
- Short Name:
- J/AJ/159/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Transiting Exoplanet Survey Satellite (TESS) is finding transiting planet candidates around bright, nearby stars across the entire sky. The large field of view, however, results in low spatial resolution; therefore, multiple stars contribute to almost every TESS light curve. High angular resolution imaging can detect the previously unknown companions to planetary candidate hosts that dilute the transit depths, lead to host star ambiguity, and, in some cases, are the source of false-positive transit signals. We use speckle imaging on the Southern Astrophysical Research (SOAR) telescope to search for companions to 542 TESS planet candidate hosts in the southern sky. We provide correction factors for the 117 systems with resolved companions due to photometric contamination. The contamination in TESS due to close binaries is similar to that found in surveys of Kepler planet candidates. For the solar-type population, we find a deep deficit of close binary systems with projected stellar separations less than 100 au among planet candidate hosts (44 observed binaries compared to 124 expected based on field binary statistics). The close binary suppression among TESS planet candidate hosts is similar to that seen for the more distant Kepler population. We also find a large surplus of TESS planet candidates in wide binary systems detected in both SOAR and Gaia DR2 (Cat. I/345) (119 observed binaries compared to 77 expected). These wide binaries almost exclusively host giant planets, however, suggesting that orbital migration caused by perturbations from the stellar companion may lead to planet-planet scattering and suppress the population of small planets in wide binaries. Both trends are also apparent in the M dwarf planet candidate hosts.
- ID:
- ivo://CDS.VizieR/J/AJ/147/85
- Title:
- Solar neighborhood. XXXIII. 45 M dwarfs
- Short Name:
- J/AJ/147/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present basic observational data and association membership analysis for 45 young and active low-mass stellar systems from the ongoing Research Consortium On Nearby Stars photometry and astrometry program at the Cerro Tololo Inter-American Observatory. Most of these systems have saturated X-ray emission (log(L_X_/L_bol_)>-3.5) based on X-ray fluxes from the ROSAT All-Sky Survey, and many are significantly more luminous than main-sequence stars of comparable color. We present parallaxes and proper motions, Johnson-Kron-Cousins VRI photometry, and multiplicity observations from the CTIOPI program on the CTIO 0.9m telescope. To this we add low-resolution optical spectroscopy and line measurements from the CTIO 1.5m telescope, and interferometric binary measurements from the Hubble Space Telescope Fine Guidance Sensors. We also incorporate data from published sources: JHK_S_ photometry from the Two Micron All Sky Survey point source catalog, X-ray data from the ROSAT All-Sky Survey, and radial velocities from literature sources. Within the sample of 45 systems, we identify 21 candidate low-mass pre-main-sequence members of nearby associations, including members of {beta} Pictoris, TW Hydrae, Argus, AB Doradus, two ambiguous {approx}30Myr old systems, and one object that may be a member of the Ursa Major moving group. Of the 21 candidate young systems, 14 are newly identified as a result of this work, and six of those are within 25pc of the Sun.
- ID:
- ivo://CDS.VizieR/J/AJ/147/94
- Title:
- Solar neighborhood. XXXII. L and M dwarfs
- Short Name:
- J/AJ/147/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We construct a Hertzsprung-Russell diagram for the stellar/substellar boundary based on a sample of 63 objects ranging in spectral type from M6V to L4. We report newly observed VRI photometry for all 63 objects and new trigonometric parallaxes for 37 objects. The remaining 26 objects have trigonometric parallaxes from the literature. We combine our optical photometry and trigonometric parallaxes with 2MASS and WISE photometry and employ a novel spectral energy distribution fitting algorithm to determine effective temperatures, bolometric luminosities, and radii. Our uncertainties range from ~20K to ~150K in temperature, ~0.01 to ~0.06 in log (L/L_{sun}_) and ~3% to ~10% in radius. We check our methodology by comparing our calculated radii to radii directly measured via long baseline optical interferometry. We find evidence for the local minimum in the radius-temperature and radius-luminosity trends that signals the end of the stellar main sequence and the start of the brown dwarf sequence at T_eff_~2075K, log(L/L_{sun}_)~-3.9, and (R/R_{sun}_)~0.086. The existence of this local minimum is predicted by evolutionary models, but at temperatures ~400K cooler. The minimum radius happens near the locus of 2MASS J0523-1403, an L2.5 dwarf with V-K=9.42. We make qualitative arguments as to why the effects of the recent revision in solar abundances accounts for the discrepancy between our findings and the evolutionary models. We also report new color-absolute magnitude relations for optical and infrared colors which are useful for estimating photometric distances. We study the optical variability of all 63 targets and find an overall variability fraction of 36_-7_^+9^% at a threshold of 15mmag in the I band, which is in agreement with previous studies.
- ID:
- ivo://CDS.VizieR/J/AJ/154/32
- Title:
- Solar neighborhood. XXXIX. Nearby white dwarfs
- Short Name:
- J/AJ/154/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 114 trigonometric parallaxes for 107 nearby white dwarf (WD) systems from both the Cerro Tololo Inter-American Observatory Parallax Investigation (CTIOPI) and the U. S. Naval Observatory Flagstaff Station (NOFS) parallax programs. Of these, 76 parallaxes for 69 systems were measured by the CTIOPI program and 38 parallaxes for as many systems were measured by the NOFS program. A total of 50 systems are confirmed to be within the 25-pc horizon of interest. Coupled with a spectroscopic confirmation of a common proper-motion companion to a Hipparcos star within 25pc as well as confirmation parallax determinations for two WD systems included in the recently released Tycho Gaia Astrometric Solution catalog, we add 53 new systems to the 25-pc WD sample-a 42% increase. Our sample presented here includes four strong candidate halo systems, a new metal-rich DAZ WD, a confirmation of a recently discovered nearby short-period (P=2.85hr) double degenerate, a WD with a new astrometric perturbation (long period, unconstrained with our data), and a new triple system where the WD companion main-sequence star has an astrometric perturbation (P~1.6year).
- ID:
- ivo://CDS.VizieR/J/AJ/149/5
- Title:
- Solar neighborhood. XXXV. Distances to M dwarfs
- Short Name:
- J/AJ/149/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present trigonometric, photometric, and photographic distances to 1748 southern ({delta}{<=}O{deg}) M dwarf systems with {mu}>=0.18''/yr, of which 1404 are believed to lie within 25pc of the Sun. The stars have 6.67{<=}V_J_{<=}21.38 and 3.50{<=}(V_J_-K_S_){<=}9.27, covering the entire M dwarf spectral sequence from M0.0 V through M9.5 V. This sample therefore provides a comprehensive snapshot of our current knowledge of the southern sky for the nearest M dwarfs that dominate the stellar population of the Galaxy. Roughly one-third of the 1748 systems, each of which has an M dwarf primary, have published high quality parallaxes, including 179 from the REsearch Consortium On Nearby Stars astrometry program. For the remaining systems, we offer photometric distance estimates that have well-calibrated errors. The bulk of these (~700) are based on new V_J_R_KC_I_KC_ photometry acquired at the CTIO/SMARTS 0.9m telescope, while the remaining 500 primaries have photographic plate distance estimates calculated using SuperCOSMOS B_J_R_59F_I_IVN_ photometry. Confirmed and candidate subdwarfs in the sample have been identified, and a census of companions is included.
