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- ID:
- ivo://CDS.VizieR/J/AJ/127/1727
- Title:
- Differential magnitudes of binary stars
- Short Name:
- J/AJ/127/1727
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Five hundred seventy-six magnitude difference measures are presented for 260 binary stars. These measures are derived from CCD-based speckle observations taken at the WIYN 3.5m telescope at Kitt Peak National Observatory during the period 1997-2000. Separations of the systems range from over 1" down to near the diffraction limit of the telescope. A study of multiple measures of the same targets indicates that the measures have a typical uncertainty of better than 0.13mag per 2 minute observation, and that multiple observations can be averaged to arrive at smaller uncertainties. Results presented here are also compared, insofar as it is possible, with measures in the Hipparcos Catalogue and to previous studies using adaptive optics. No major systematic errors were identified.
- ID:
- ivo://CDS.VizieR/J/AJ/158/141
- Title:
- Differential photometry & RVs of HAT-P-69 & HAT-P-70
- Short Name:
- J/AJ/158/141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Wide-field surveys for transiting planets are well suited to searching diverse stellar populations, enabling a better understanding of the link between the properties of planets and their parent stars. We report the discovery of HAT-P-69 b (TOI 625.01) and HAT-P-70 b (TOI 624.01), two new hot Jupiters around A stars from the Hungarian-made Automated Telescope Network (HATNet) survey that have also been observed by the Transiting Exoplanet Survey Satellite. HAT-P-69 b has a mass of 3.58_-0.58_^+0.58^ M_Jup_ and a radius of 1.676_-0.033_^+0.051^ R_Jup_ and resides in a prograde 4.79 day orbit. HAT-P-70 b has a radius of 1.87_-0.10_^+0.15^ R_Jup_ and a mass constraint of <6.78 (3{sigma}) M_Jup_ and resides in a retrograde 2.74 day orbit. We use the confirmation of these planets around relatively massive stars as an opportunity to explore the occurrence rate of hot Jupiters as a function of stellar mass. We define a sample of 47126 main-sequence stars brighter than T_mag_=10 that yields 31 giant planet candidates, including 18 confirmed planets, 3 candidates, and 10 false positives. We find a net hot Jupiter occurrence rate of 0.41+/-0.10% within this sample, consistent with the rate measured by Kepler for FGK stars. When divided into stellar mass bins, we find the occurrence rate to be 0.71+/-0.31% for G stars, 0.43+/-0.15% for F stars, and 0.26+/-0.11% for A stars. Thus, at this point, we cannot discern any statistically significant trend in the occurrence of hot Jupiters with stellar mass.
- ID:
- ivo://CDS.VizieR/J/PASP/122/162
- Title:
- Direct imaging of exoplanets
- Short Name:
- J/PASP/122/162
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-contrast imaging can find and characterize gas giant planets around nearby young stars and the closest M stars, complementing radial velocity and astrometric searches by exploring orbital separations inaccessible to indirect methods. Ground-based coronagraphs are already probing within 25AU of nearby young stars to find objects as small as 3M_{Jup}_. This paper contrasts near-term and future ground-based capabilities with high-contrast imaging modes of the James Webb Space Telescope (JWST). Monte Carlo modeling reveals that JWST can detect planets with masses as small as 0.2M_{Jup}_ across a broad range of orbital separations. We present new calculations for planet brightness as a function of mass and age for specific JWST filters and extending to 0.1M_{Jup}_.
- ID:
- ivo://CDS.VizieR/J/A+A/648/A73
- Title:
- Discovery of the directly imaged planet YSES 2b
- Short Name:
- J/A+A/648/A73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To understand the origin and formation pathway of wide-orbit gas giant planets, it is necessary to expand the limited sample of these objects. The mass of exoplanets derived with spectrophotometry, however, varies strongly as a function of the age of the system and the mass of the primary star. By selecting stars with similar ages and masses, the Young Suns Exoplanet Survey (YSES) aims to detect and characterize planetary-mass companions to solar-type host stars in the Scorpius-Centaurus association. Our survey is carried out with VLT/SPHERE with short exposure sequences on the order of 5-min per star per filter. The subtraction of the stellar point spread function (PSF) is based on reference star differential imaging (RDI) using the other targets (with similar colors and magnitudes) in the survey in combination with principal component analysis. Two astrometric epochs that are separated by more than one year are used to confirm co-moving companions by proper motion analysis. We report the discovery of YSES 2b, a co-moving, planetary-mass companion to the K1 star YSES 2 (TYC 8984-2245-1, 2MASS J11275535-6626046). The primary has a Gaia EDR3 distance of 110pc, and we derive a revised mass of 1.1M_{sun}_ and an age of approximately 14Myr. We detect the companion in two observing epochs southwest of the star at a position angle of 205{deg} and with a separation of ~1.05", which translates to a minimum physical separation of 115au at the distance of the system. Photometric measurements in the H and Ks bands are indicative of a late L spectral type, similar to the innermost planets around HR 8799. We derive a photometric planet mass of 6.3^+1.6^_-0.9_M_{Jup}_ using AMES-COND and AMES-dusty evolutionary models; this mass corresponds to a mass ratio of q=(0.5+/-0.1)% with the primary. This is the lowest mass ratio of a direct imaging planet around a solar-type star to date. We discuss potential formation mechanisms and find that the current position of the planet is compatible with formation by disk gravitational instability, but its mass is lower than expected from numerical simulations. Formation via core accretion must have occurred closer to the star, yet we do not find evidence that supports the required outward migration, such as via scattering off another undiscovered companion in the system. We can exclude additional companions with masses greater than 13M_{Jup}_ in the full field of view of the detector (0.15"<{rho}<5.50"), at 0.5" we can rule out further objects that are more massive than 6M_{Jup}_, and for projected separations {rho}>2arcsec we are sensitive to planets with masses as low as 2M_{Jup}_. YSES 2b is an ideal target for follow-up observations to further the understanding of the physical and chemical formation mechanisms of wide-orbit Jovian planets. The YSES strategy of short snapshot observations (<=5min) and PSF subtraction based on a large reference library proves to be extremely efficient and should be considered for future direct imaging surveys.
- ID:
- ivo://CDS.VizieR/J/A+A/631/A108
- Title:
- Disks around post-AGB binaries fit results
- Short Name:
- J/A+A/631/A108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Post-asymptotic giant branch (pAGB) binaries are surrounded by circumbinary disks of gas and dust that are similar to protoplanetary disks found around young stars. We aim to understand the structure of these disks and identify the physical phenomena at play in their very inner regions. We want to understand the disk-binary interaction and to further investigate the comparison with protoplanetary disks. We conducted an interferometric snapshot survey of 23 post-AGB binaries in the near-infrared (H-band) using VLTI/PIONIER. We fit the multi-wavelength visibilities and closure phases with purely geometrical models with an increasing complexity (including two point-sources, an azimuthally modulated ring, and an over-resolved flux) in order to retrieve the sizes, temperatures, and flux ratios of the different components. All sources are resolved and the different components contributing to the H-band flux are dissected. The environment of these targets is very complex: 13/23 targets need models with thirteen or more parameters to fit the data. We find that the inner disk rims follow and extend the size-luminosity relation established for disks around young stars with an offset toward larger sizes. The measured temperature of the near-infrared circumstellar emission of post-AGB binaries is lower (Tsub~1200K) than for young stars, which is probably due to a different dust mineralogy and/or gas density in the dust sublimation region. The dusty inner rims of the circumbinary disks around post-AGB binaries are ruled by dust sublimation physics. Additionally a significant amount of the circumstellar $H$-band flux is over-resolved (more than 10% of the non-stellar flux is over-resolved in 14 targets). This hints that a source of unknown origin, either a disk structure or outflow. The amount of over-resolved flux is larger than around young stars. Due to the complexity of these targets, interferometric imaging is a necessary tool to reveal the interacting inner regions in a model-independent way.
- ID:
- ivo://CDS.VizieR/J/MNRAS/457/133
- Title:
- Displaced red and blue components objects
- Short Name:
- J/MNRAS/457/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a feasibility study to determine the effectiveness of using USNO-B1.0 data to preferentially detect objects with displaced red and blue components. A procedure was developed to search catalogue entries for such objects, which include M dwarfs paired with white dwarfs or with earlier main-sequence stars, and galaxies with asymmetric colour distributions. Residual differences between red and blue and infrared and blue scanned emulsion images define vectors, which, when appropriately aligned and of sufficient length, signal potential candidates. Test sample sets were analysed to evaluate the effective discrimination of the technique. Over 91000 USNO-B1.0 catalogue entries at points throughout the celestial sphere were then filtered for acceptable combinations of entry observations and magnitudes and the resulting total of about 17000 entries was winnowed down to a little more than 200 objects of interest. These were screened by visual examination of photo images to a final total of 146 candidates. About one quarter of these candidates coincide with SDSS (Sloan Digital Sky Survey) data. Those constituents fall into two groups, single and paired objects. SDSS identified several galaxies in the first group. Regarding the second group, at least half of its members were tentatively identified as main-sequence pairs, the greater portion being of widely separated spectral types. Two white dwarf-main-sequence pairs were also identified. Most importantly, the vectors formed from USNO-B1.0 residuals were in alignment with corresponding SDSS pair position angles, thereby supporting this work's central thesis.
- ID:
- ivo://CDS.VizieR/J/AJ/155/165
- Title:
- Dissipation in exoplanet hosts from tidal spin-up
- Short Name:
- J/AJ/155/165
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stars with hot Jupiters (HJs) tend to rotate faster than other stars of the same age and mass. This trend has been attributed to tidal interactions between the star and planet. A constraint on the dissipation parameter Q_*_' follows from the assumption that tides have managed to spin up the star to the observed rate within the age of the system. This technique was applied previously to HATS-18 and WASP-19. Here, we analyze the sample of all 188 known HJs with an orbital period <3.5 days and a "cool" host star (T_eff_<6100 K). We find evidence that the tidal dissipation parameter (Q_*_') increases sharply with forcing frequency, from 10^5^ at 0.5 day^-1^ to 10^7^ at 2 day^-1^. This helps to resolve a number of apparent discrepancies between studies of tidal dissipation in binary stars, HJs, and warm Jupiters. It may also allow for a HJ to damp the obliquity of its host star prior to being destroyed by tidal decay.
- ID:
- ivo://CDS.VizieR/J/MNRAS/492/2709
- Title:
- Double-lined spectroscopic binaries catalog
- Short Name:
- J/MNRAS/492/2709
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of a selected set of 69 double-lined spectroscopic binaries (SB2) with well defined visual and spectroscopic orbits was carried out. The orbital parallax, the mass, the colour, and the luminosity of each component were derived from observational data for almost all of these systems. We have also obtained an independent estimation of the component masses by comparing the colour-luminosity diagram (CMD) to the stellar evolution tracks reported by Pietrinferni. Nearly all of the observational points on the CMD are located between two tracks of slightly different mass or which fall very close to the one corresponding to a unique mass value. The masses obtained from the stellar model are in good agreement with their empirical values determined by parallax techniques (orbital, dynamical, and Gaia). This means that our adopted model is rather reliable and can therefore be used to infer further information, such as the age of each component in the studied systems. Our results indicate a fair correspondence between the age of primaries and secondary stars within 3{sigma}. Nevertheless, we caution that these age indications suffer of uncertainties due to both inhomogeneities/low precision of the adopted photometric data and possible systematics. Finally, it is statistically shown that along with the orbital and trigonometric parallaxes, the dynamical parallax can serve as a reliable tool for distance estimates.
- ID:
- ivo://CDS.VizieR/J/AJ/157/78
- Title:
- Double & multiple star systems from GaiaDR2
- Short Name:
- J/AJ/157/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Binary and multiple stars have long provided an effective empirical method of testing stellar formation and evolution theories. In particular, the existence of wide binary systems (separations >20000 au) is particularly challenging to binary formation models as their physical separations are beyond the typical size of a collapsing cloud core (~5000-10000 au). We mined the recently published Gaia-DR2 catalog (Cat. I/345) to identify bright comoving systems in the five-dimensional space (sky position, parallax, and proper motion). We identified 3741 comoving binary and multiple stellar candidate systems, out of which 575 have compatible radial velocities for all the members of the system. The candidate systems have separations between ~400 and 500000 au. We used the analysis tools of the Virtual Observatory to characterize the comoving system members and to assess their reliability. The comparison with previous comoving systems catalogs obtained from TGAS showed that these catalogs contain a large number of false systems. In addition, we were not able to confirm the ultra-wide binary population presented in these catalogs. The robustness of our methodology is demonstrated by the identification of well known comoving star clusters and by the low contamination rate for comoving binary systems with projected physical separations <50000 au. These last constitute a reliable sample for further studies. The catalog is available online at the Spanish Virtual Observatory portal (http://svo2.cab.inta-csic.es/vocats/v2/comovingGaiaDR2/).