- ID:
- ivo://CDS.VizieR/J/A+A/454/581
- Title:
- Iron abundances of 33 wide binaries
- Short Name:
- J/A+A/454/581
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-precision iron abundance differences for 33 wide binaries with similar components. They were observed with the FEROS spectrograph at ESO, looking for abundance anomalies due to the ingestion of metal rich material of a planetary origin. ************************************************************************** * * * Sorry, but the author(s) never supplied the tabular material * * announced in the paper * * * **************************************************************************
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Search Results
- ID:
- ivo://CDS.VizieR/J/PAZh/27/393
- Title:
- IR photometry of five long-period binaries
- Short Name:
- J/PAZh/27/393
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- JHKLM photometry for five long-period binaries is presented. For a description of the UBVR and JHKLM photometric systems, see e.g. <GCPD/08> and <GCPD/09> respectively.
- ID:
- ivo://CDS.VizieR/J/ApJ/657/1013
- Title:
- IR photometry of 2MASS/Spitzer white dwarfs
- Short Name:
- J/ApJ/657/1013
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We review the available near- and mid-infrared photometry for white dwarfs obtained from the Two Micron All Sky Survey (2MASS) and by the Spitzer Space Telescope. Both data sets have recently been used to seek white dwarfs with infrared excesses due to the presence of unresolved companions or circumstellar disks, and also to derive the atmospheric parameters of cool white dwarfs. We first attempt to evaluate the reliability of the 2MASS photometry by comparing it with an independent set of published JHK CIT magnitudes for 160 cool white dwarf stars, and also by comparing the data with the predictions of detailed model atmosphere calculations. The possibility of using 2MASS to identify unresolved M dwarf companions or circumstellar disks is then discussed.
- ID:
- ivo://CDS.VizieR/J/AJ/126/1526
- Title:
- IR photometry of ultracool dwarfs
- Short Name:
- J/AJ/126/1526
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) observations of a sample of 134 ultracool objects (spectral types later than M7) coming from the Deep Near Infrared Survey (DENIS), Two Micron All Sky Survey (2MASS), and Sloan Digital Sky Survey (SDSS), with distances estimated to range from 7 to 105pc. Fifteen new ultracool binary candidates are reported here. Eleven known binaries are confirmed, and orbital motion is detected in some of them. We estimate that the closest binary systems in this sample have periods between 5 and 20yr, and thus dynamical masses will be derived in the near future. For the calculation of binary frequency, we restrict ourselves to systems with distances less than 20pc. After correction of the binaries bias, we find a ratio of visual binaries (at the HST limit of detection) of around 10%, and that 15% of the 26 objects within 20pc are binary systems with separations between 1 and 8AU. The observed frequency of ultracool binaries is similar to that of binaries with G-type primaries in the separation range from 2.1 to 140AU. There is also a clear deficit of ultracool binaries with separations greater than 15AU, and a possible tendency for the binaries to have mass ratios near unity. Most systems have indeed visual and near-infrared brightness ratios between 1 and 0.3. We discuss our results in the framework of current scenarios for the formation and evolution of free-floating brown dwarfs.
- ID:
- ivo://CDS.VizieR/J/A+A/585/A126
- Title:
- 3 irradiated and bloated hot Jupiters RV and phot.
- Short Name:
- J/A+A/585/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on three new transiting hot Jupiter planets, discovered from the WASP surveys, which we combine with radial velocities from OHP/SOPHIE and Euler/CORALIE and photometry from Euler and TRAPPIST. The planets WASP-76b, WASP-82b, and WASP-90b are all inflated, with radii of 1.7-1.8R_Jup_. All three orbit hot stars, of type F5-F7, with orbits of 1.8-3.9d, and all three stars have evolved, post-main-sequence radii (1.7-2.2R_{sun}_). Thus the three planets fit a known trend of hot Jupiters that receive high levels of irradiation, as a result of their being highly inflated. We caution, though, about the presence of a selection effect, in that non-inflated planets around ~2R_{sun}_ post-MS stars can often produce transits too shallow to be detected by the ground-based surveys that have found the majority of transiting hot Jupiters.
- ID:
- ivo://CDS.VizieR/J/ApJ/743/85
- Title:
- IRS multi-epoch observations of HD 69830
- Short Name:
- J/ApJ/743/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The main-sequence solar-type star HD 69830 has an unusually large amount of dusty debris orbiting close to three planets found via the radial velocity technique. In order to explore the dynamical interaction between the dust and planets, we have performed multi-epoch photometry and spectroscopy of the system over several orbits of the outer dust. We find no evidence for changes in either the dust amount or its composition, with upper limits of 5%-7% (1{sigma} per spectral element) on the variability of the dust spectrum over 1 year, 3.3% (1{sigma}) on the broadband disk emission over 4 years, and 33% (1{sigma}) on the broadband disk emission over 24 years. Detailed modeling of the spectrum of the emitting dust indicates that the dust is located outside of the orbits of the three planets and has a composition similar to main-belt, C-type asteroids in our solar system. Additionally, we find no evidence for a wide variety of gas species associated with the dust. Our new higher signal-to-noise spectra do not confirm our previously claimed detection of H_2_O ice leading to a firm conclusion that the debris can be associated with the break-up of one or more C-type asteroids formed in the dry, inner regions of the protoplanetary disk of the HD 69830 system. The modeling of the spectral energy distribution and high spatial resolution observations in the mid-infrared are consistent with a ~1 AU location for the emitting material.
- ID:
- ivo://CDS.VizieR/J/ApJS/119/83
- Title:
- IUE sample of binaries with hot component
- Short Name:
- J/ApJS/119/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained or retrieved IUE spectra for over 100 middle- and late-type giant and supergiant stars whose spectra indicate the presence of a hot component earlier than type F2. The hot companions are classified accurately by temperature class from their far-UV spectra. The interstellar extinction of each system and the relative luminosities of the components are derived from analysis of the UV and optical fluxes, using a grid of UV intrinsic colors for hot dwarfs. We find that there is fair agreement in general between current UV spectral classification and ground-based hot component types, in spite of the difficulties of assigning the latter. There are a few cases in which the cool component optical classifications disagree considerably with the temperature classes inferred from our analysis of UV and optical photometry. The extinction parameter agrees moderately well with other determinations of B-V color excess. Many systems are worthy of further study especially to establish their spectroscopic orbits. Further work is planned to estimate luminosities of the cool components from the data herein; in many cases, these luminosities' accuracies should be comparable to or exceed those of the Hipparcos parallaxes.
- ID:
- ivo://CDS.VizieR/J/AJ/152/182
- Title:
- iz follow-up photometry of HAT-P-65 and HAT-P-66
- Short Name:
- J/AJ/152/182
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of the transiting exoplanets HAT-P-65b and HAT-P-66b, with orbital periods of 2.6055 and 2.9721 days, masses of 0.527+/-0.083M_J_ and 0.783+/-0.057M_J_, and inflated radii of 1.89+/-0.13R_J_ and 1.59_-0.10_^+0.16^R_J_, respectively. They orbit moderately bright (V=13.145+/-0.029 and V=12.993+/-0.052) stars of mass 1.212+/-0.050M_{Sun}_ and 1.255_-0.054_^+0.107^M_{Sun}_. The stars are at the main-sequence turnoff. While it is well known that the radii of close-in giant planets are correlated with their equilibrium temperatures, whether or not the radii of planets increase in time as their hosts evolve and become more luminous is an open question. Looking at the broader sample of well-characterized close-in transiting giant planets, we find that there is a statistically significant correlation between planetary radii and the fractional ages of their host stars, with a false-alarm probability of only 0.0041%. We find that the correlation between the radii of planets and the fractional ages of their hosts is fully explained by the known correlation between planetary radii and their present-day equilibrium temperatures; however, if the zero-age main-sequence equilibrium temperature is used in place of the present-day equilibrium temperature, then a correlation with age must also be included to explain the planetary radii. This suggests that, after contracting during the pre-main-sequence, close-in giant planets are reinflated over time due to the increasing level of irradiation received from their host stars. Prior theoretical work indicates that such a dynamic response to irradiation requires a significant fraction of the incident energy to be deposited deep within the planetary interiors.
- ID:
- ivo://CDS.VizieR/J/AJ/160/115
- Title:
- JHK observation of 75 OB stars in Cyg OB2
- Short Name:
- J/AJ/160/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a high angular resolution survey of massive OB stars in the Cygnus OB2 association that we conducted with the Near-Infrared Imager camera and ALTAIR adaptive optics system of the Gemini North telescope. We observed 74 O- and early-B-type stars in Cyg OB2 in the JHK infrared bands in order to detect binary and multiple companions. The observations are sensitive to equal-brightness pairs at separations as small as 0.08", and progressively fainter companions are detectable out to {Delta}K=9mag at a separation of 2". This faint contrast limit due to read noise continues out to 10" near the edge of the detector. We assigned a simple probability of chance alignment to each companion based upon its separation and magnitude difference from the central target star and upon areal star counts for the general star field of Cyg OB2. Companion stars with a field membership probability of less than 1% are assumed to be physical companions. This assessment indicates that 47% of the targets have at least one resolved companion that is probably gravitationally bound. Including known spectroscopic binaries, our sample includes 27 binary, 12 triple, and 9 systems with 4 or more components. These results confirm studies of high-mass stars in other environments that find that massive stars are born with a high-multiplicity fraction. The results are important for the placement of the stars in the Hertzsprung-Russell diagram, the interpretation of their spectroscopic analyses, and for future mass determinations through measurement of orbital motion.
- ID:
- ivo://CDS.VizieR/J/A+A/375/989
- Title:
- JHK photometry of Praesepe low-mass stars
- Short Name:
- J/A+A/375/989
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File table 1 contains the list of low-mass Praesepe stars observed with adaptive optics and which were not resolved as multiple systems.
