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1481. Binary stars in Upper Scorpius
ID:
ivo://CDS.VizieR/J/AJ/159/15
Title:
Binary stars in Upper Scorpius
Short Name:
J/AJ/159/15
Date:
21 Oct 2021
Publisher:
CDS
Description:
To address the statistics of binary stars in the 8 Myr old Upper Scorpius (USco) star formation region, we conducted a speckle interferometric survey of 614 association members more massive than 0.4 M_{sun}_ (spectral types earlier than M3V) based on the list of Luhman et al. (2018, J/AJ/156/271). We resolved 187 pairs, 55 of which are new discoveries. Also using the published data and the Gaia DR2 (Cat. I/345), a catalog of 250 physical binaries was produced. We carefully estimated detection limits for each target and studied binary statistics in the separation range from 0.06" to 20" (9-2800 au), as well as clustering at larger separations. The frequency of companions with mass ratios q>0.3 in this separation range is 0.33+/-0.04 and 0.35+/-0.04 for early M- and solar-type stars, respectively, larger by 1.62+/-0.22 and 1.39+/-0.18 times compared to field stars of similar masses. The excess is produced mostly by pairs closer than 100 au. At separations from 100 to 10^4^ au, the separation distribution and companion fraction resemble those of solar-type stars in the field. However, unlike in the field, we see a relative deficit of equal-mass binaries at separations of ~500 au, compared to smaller and larger separations. The distribution of q depends on the separation, with a preference of larger q and a larger fraction of twins with q>0.95 at smaller separations. The binary population of USco differs from binaries in the field in several ways and suggests that binary statistics is not universal.
1482. Binary stars parameters from LAMOST & Kepler obs.
ID:
ivo://CDS.VizieR/J/ApJS/244/43
Title:
Binary stars parameters from LAMOST & Kepler obs.
Short Name:
J/ApJS/244/43
Date:
21 Oct 2021
Publisher:
CDS
Description:
The parameter distribution of binaries is a fundamental knowledge of the stellar systems. A statistical study on the binary stars is carried out based on the LAMOST spectral and Kepler photometric database. We presented a catalog of 1320 binary stars with plentiful parameters, including period, binary subtype, atmosphere parameters (Teff, [Fe/H], and logg), and the physical properties, such as mass, radius, and age, for the primary component stars. Based on this catalog, the unbiased distribution, rather than the observed distribution, was obtained after the correction of selection biases by the Monte Carlo method considering comprehensive affecting factors. For the first time, the orbital eccentricity distribution of the detached binaries is presented. The distribution differences between the three subtypes of binaries (detached, semidetached, and contact) are demonstrated, which can be explained by the generally accepted evolutional scenarios. Many characteristics of the binary stars, such as huge mass transfer on semidetached binaries, period cutoff on contact binaries, period-temperature relationship of contact binaries, and the evolved binaries, are reviewed by the new database. This work supports a common evolutionary scenario for all subtypes of binary stars.
1483. Binary star speckle measurements
ID:
ivo://CDS.VizieR/J/A+AS/105/503
Title:
Binary star speckle measurements
Short Name:
J/A+AS/105/503
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have continued to survey visual and interferometric binary stars with significant orbital motion by means of speckle method at the telescopes of the Special Astrophysical Observatory (SAO) in Zelenchuk. Here we present the lists of 267 speckle observations made with the 6 m and the 1 m telescopes in the period May 1989 - November 1993.
1484. Binary stellar evolution data for Kepler systems
ID:
ivo://CDS.VizieR/J/ApJ/832/183
Title:
Binary stellar evolution data for Kepler systems
Short Name:
J/ApJ/832/183
Date:
21 Oct 2021
Publisher:
CDS
Description:
Inspired by the recent Kepler discoveries of circumbinary planets orbiting nine close binary stars, we explore the fate of the former as the latter evolve off the main sequence. We combine binary star evolution models with dynamical simulations to study the orbital evolution of these planets as their hosts undergo common-envelope (CE) stages, losing in the process a tremendous amount of mass on dynamical timescales. Five of the systems experience at least one Roche-lobe overflow and CE stage (Kepler-1647 experiences three), and the binary stars either shrink to very short orbits or coalesce; two systems trigger a double-degenerate supernova explosion. Kepler's circumbinary planets predominantly remain gravitationally bound at the end of the CE phase, migrate to larger orbits, and may gain significant eccentricity; their orbital expansion can be more than an order of magnitude and can occur over the course of a single planetary orbit. The orbits these planets can reach are qualitatively consistent with those of the currently known post-CE, eclipse-time variations circumbinary candidates. Our results also show that circumbinary planets can experience both modes of orbital expansion (adiabatic and nonadiabatic) if their host binaries undergo more than one CE stage; multiplanet circumbinary systems like Kepler-47 can experience both modes during the same CE stage. Additionally, unlike Mercury orbiting the Sun, a circumbinary planet with the same semimajor axis can survive the CE evolution of a close binary star with a total mass of 1M_{sun}_.
1485. Binary systems among nearby dwarfs searching
ID:
ivo://CDS.VizieR/J/PAZh/44/124
Title:
Binary systems among nearby dwarfs searching
Short Name:
J/PAZh/44/124
Date:
21 Oct 2021
Publisher:
CDS
Description:
Our goal is to find previously unknown binary systems among low-mass dwarfs in the solar neighborhood and to test the search technique. The basic ideas are to reveal the images of stars with significant ellipticities and/or asymmetries compared to the background stars on CCD frames and to subsequently determine the spatial parameters of the binary system and the magnitude difference between its components. For its realization we have developed a method based on an image shapelet decomposition. All of the comparatively faint stars with large proper motions (Vmag>13^m^, {mu}>300mas/yr) for which the 'duplicate source' flag in the Gaia DR1 catalogue is equal to one have been included in the list of objects for our study. As a result, we have selected 702 stars. To verify our results, we have performed additional observations of 65 stars from this list with the Pulkovo 1-m 'Saturn' telescope (2016-2017). We have revealed a total of 138 binary candidates (nine of them from the `Saturn' telescope and SDSS data). Six program stars are known binaries. The images of the primaries of the comparatively wide pairs WDS 14519+5147, WDS 11371+6022, and WDS 15404+2500 are shown to be resolved into components; therefore, we can talk about the detection of triple systems. The angular separation {rho}, position angle, and component magnitude difference {Delta}m have been estimated for almost all of the revealed binary systems. For most stars 1.5''<{rho}<2.5'', while {Delta}m<1.5^m^.
1486. Binary systems in Taurus-Auriga
ID:
ivo://CDS.VizieR/J/ApJ/745/19
Title:
Binary systems in Taurus-Auriga
Short Name:
J/ApJ/745/19
Date:
21 Oct 2021
Publisher:
CDS
Description:
The past decade has seen a revolution in our understanding of protoplanetary disk evolution and planet formation in single-star systems. However, the majority of solar-type stars form in binary systems, so the impact of binary companions on protoplanetary disks is an important element in our understanding of planet formation. We have compiled a combined multiplicity/disk census of Taurus-Auriga, plus a restricted sample of close binaries in other regions, in order to explore the role of multiplicity in disk evolution. Our results imply that the tidal influence of a close (<=40AU) binary companion significantly hastens the process of protoplanetary disk dispersal, as ~2/3 of all close binaries promptly disperse their disks within <~1Myr after formation. However, prompt disk dispersal only occurs for a small fraction of wide binaries and single stars, with ~80%-90% retaining their disks for at least ~2-3Myr (but rarely for more than ~5Myr). Our new constraints on the disk clearing timescale have significant implications for giant planet formation; most single stars have 3-5Myr within which to form giant planets, whereas most close binary systems would have to form giant planets within <~1Myr. If core accretion is the primary mode for giant planet formation, then gas giants in close binaries should be rare. Conversely, since almost all single stars have a similar period of time within which to form gas giants, their relative rarity in radial velocity (RV) surveys indicates either that the giant planet formation timescale is very well matched to the disk dispersal timescale or that features beyond the disk lifetime set the likelihood of giant planet formation.
1487. Binary white dwarfs atmospheric parameters
ID:
ivo://CDS.VizieR/J/ApJ/794/35
Title:
Binary white dwarfs atmospheric parameters
Short Name:
J/ApJ/794/35
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a detailed spectroscopic analysis of 61 low-mass white dwarfs and provide precise atmospheric parameters, masses, and updated binary system parameters based on our new model atmosphere grids and the most recent evolutionary model calculations. For the first time, we measure systematic abundances of He, Ca, and Mg for metal-rich, extremely low mass white dwarfs and examine the distribution of these abundances as a function of effective temperature and mass. Based on our preliminary results, we discuss the possibility that shell flashes may be responsible for the presence of the observed He and metals. We compare stellar radii derived from our spectroscopic analysis to model-independent measurements and find good agreement except for white dwarfs with T_eff_<~10000 K. We also calculate the expected gravitational wave strain for each system and discuss their significance to the eLISA space-borne gravitational wave observatory. Finally, we provide an update on the instability strip of extremely low mass white dwarf pulsators.
1488. BINOCS: NEWFIRM & IRAC IR photometry of clusters
ID:
ivo://CDS.VizieR/J/AJ/161/160
Title:
BINOCS: NEWFIRM & IRAC IR photometry of clusters
Short Name:
J/AJ/161/160
Date:
18 Jan 2022
Publisher:
CDS
Description:
We introduce a new binary detection technique, Binary INformation from Open Clusters using SEDs (binocs), which we show is able to determine reliable stellar multiplicity and masses over a much larger mass range than current approaches. This new technique determines accurate component masses of binary and single systems of the open clusters' main sequence by comparing observed magnitudes from multiple photometric filters to synthetic star spectral energy distributions (SEDs), allowing us to systematically probe the binary population for low-mass stars in clusters for eight well-studied open clusters. We provide new deep, infrared photometric catalogs (1.2-8.0 {mu}m) for the key open clusters NGC 1960 (M36), NGC 2099 (M37), NGC 2420, and NGC 2682 (M67), using observations from NOAO/NEWFIRM and Spitzer/IRAC. Using these deep multiwavelength catalogs, the binocs method is applied to these clusters to determine accurate component masses for unresolved cluster binaries. We explore binary fractions as a function of cluster age, Galactic location, and metallicity.
1489. BI photometry of bulgeless galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/435/1186
Title:
BI photometry of bulgeless galaxies
Short Name:
J/MNRAS/435/1186
Date:
21 Oct 2021
Publisher:
CDS
Description:
We examine the magnitude and size evolution of bulgeless (discs with no-bulge or pseudo-bulge) galaxies up to z~0.9 in rest-frame B band. Their evolution is compared to that of normal-discs (or discs with classical bulge). The study is done for luminous sources (M_B_<=-20) in two equal-volume redshift bins (0.4<=z<0.77 and 0.77<=z<1.0) and a local range (0.02<=z<0.05). The mean surface-brightness, mu_B_, from z_mean_=0.89 to z_mean_=0.04, shows a dimming of 0.79mag/arcsec2 for bulgeless galaxies and 1.16mag/arcsec2 for normal-discs. The characteristic magnitude, M_B_, shows an increase of 0.55mag for bulgeless galaxies and 0.95mag for normal-discs. Both dimming and faintness observed since z~0.9 is more pronounced for the normal-discs by ~0.4mag. The size distribution is log-normal and both bulgeless and normal-discs show a slight increase in the mean value, <{Delta}log(R_e_)>~0.11, from z_mean_=0.89 to z_mean_=0.04. The proportion of bulgeless galaxies in the full disc sample undergoes a considerable decline with decrease in redshift. This along with the larger dimming and faintness seen for normal-discs suggests that some fraction of the bulgeless sources switch to the normal-disc morphology with time. To ascertain the validity of studying morphology in the optical, the properties of the galaxies observed in both rest-frame B and I band are compared. The common sample is more luminous in the I band but the sizes are larger in the B band for more than 74 percent of the sources. The variation in the Sersic-index values of the galaxies in the two rest-bands is minor enough to have any effect on the morphological classification.
1490. BI photometry of NGC 1407 and NGC 1400 GCs
ID:
ivo://CDS.VizieR/J/MNRAS/366/1230
Title:
BI photometry of NGC 1407 and NGC 1400 GCs
Short Name:
J/MNRAS/366/1230
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present wide-field Keck telescope imaging of the globular cluster (GC) systems around NGC 1407 and 1400 in the Eridanus galaxy cloud. This is complemented by Hubble Space Telescope (HST) images from the Advanced Camera for Surveys of NGC 1407 and Wide Field and Planetary Camera 2 images of NGC 1400.

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