- ID:
- ivo://CDS.VizieR/J/A+A/501/785
- Title:
- Discovery and characterization of WASP-6b
- Short Name:
- J/A+A/501/785
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of WASP-6b, an inflated sub-Jupiter mass planet transiting every 3.3610060^+0.0000022^_-0.0000035_days a mildly metal-poor solar-type star of magnitude V=11.9. A combined analysis of the WASP photometry, high-precision followup transit photometry and radial velocities yield a planetary mass M_p_=0.503^+0.019^_-0.038_ and radius R_p_=1.224^+0.051^_0.052_, resulting in a density {rho}_p_=0.27{+/-}0.05{rho}_J_. The mass and radius for the host star are M_*_=0.88^+0.05^-0.08_M_{sun}_ and R_*_=0.870^0.025^_-0.036_R_{sun}_. The non-zero orbital eccentricity e=0.054^+0.018^_-0.015_ that we measure suggests that the planet underwent a massive tidal heating ~1Gyr ago that could have contributed to its inflated radius. High-precision radial velocities obtained during a transit allow us to measure a sky-projected angle between the stellar spin and orbital axis {beta}=11^+14^_-18_{deg}. In addition to similar published measurements, this result favors a dominant migration mechanism based on tidal interactions with a protoplanetary disk.
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- ID:
- ivo://CDS.VizieR/J/A+A/624/A87
- Title:
- Discovery of a resolved disk around Wray 15-788
- Short Name:
- J/A+A/624/A87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Protoplanetary disks are the birth environments of planetary systems. Therefore, the study of young, circumstellar environments is essential to understanding the processes taking place in planet formation and the evolution of planetary systems. We detect and characterize circumstellar disks and potential companions around solar-type, pre-main sequence stars in the Scorpius-Centaurus association (Sco-Cen). As part of our ongoing survey we carried out high-contrast imaging with VLT/SPHERE/IRDIS to obtain polarized and total intensity images of the young (11^+16^_-7_)Myr old) K3IV star Wray 15-788 within the Lower Centaurus Crux subgroup of Sco-Cen. For the total intensity images, we remove the stellar halo via an approach based on reference star differential imaging in combination with principal component analysis. Both total intensity and polarimetric data resolve a disk around the young, solar-like Sco-Cen member Wray 15-788. Modeling of the stellar spectral energy distribution suggests that this is protoplanetary disk at a transition stage. We detect a bright outer ring at a projected separation of ~370mas (~56au), hints of inner substructures at ~170mas (~28au), and a gap in between. Within a position angle range of only 60{deg}<{phi}<240{deg}, we are confident at the 5{sigma} level that we detect actual scattered light flux from the outer ring of the disk; the remaining part is indistinguishable from background noise. For the detected part of the outer ring we determine a disk inclination of i=21{deg}+/-6{deg} and a position angle of {varphi}=76{deg}+/-16{deg}. Furthermore, we find that Wray 15-788 is part of a binary system with the A2V star HD 98363 at a separation of ~50arcsec (~6900,au). The detection of only half of the outer ring might be due to shadowing by a misaligned inner disk. A potential substellar companion can cause the misalignment of the inner structures and can be responsible for clearing the detected gap from scattering material.However, we cannot rule out the possibility of a non-detection due to our limited signal-to-noise ratio, combined with brightness azimuthal asymmetry. From our data we can exclude companions more massive than 10M_{jup}_ within the gap at a separation of ~230mas (~35au). Additional data are required to characterize the disk's peculiar morphology and to set tighter constraints on the potential perturber's orbital parameters and mass.
- ID:
- ivo://CDS.VizieR/J/MNRAS/414/1278
- Title:
- Eccentricities of transiting planets
- Short Name:
- J/MNRAS/414/1278
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The two dominant features in the distribution of orbital parameters for close-in exoplanets are the prevalence of circular orbits for very short periods, and the observation that planets on closer orbits tend to be heavier. The first feature is interpreted as a signature of tidal evolution, while the origin of the second, a 'mass-period relation' for hot Jupiters, is not understood. In this paper we reconsider the ensemble properties of transiting exoplanets with well-measured parameters, focusing on orbital eccentricity and the mass-period relation. We recalculate the constraints on eccentricity in a homogeneous way, using new radial velocity data, with particular attention to statistical biases. We find that planets on circular orbits gather in a well-defined region of the mass-period plane, close to the minimum period for any given mass. Exceptions to this pattern reported in the literature can be attributed to statistical biases. The ensemble data is compatible with classical tide theory with orbital circularization caused by tides raised on the planet, and suggest that tidal circularization and the stopping mechanisms for close-in planets are closely related to each other. The position mass-period relation is compatible with a relation between a planet's Hill radius and its present orbit.
- ID:
- ivo://CDS.VizieR/J/ApJ/709/168
- Title:
- Eccentric orbits in exoplanets
- Short Name:
- J/ApJ/709/168
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Doppler technique measures the reflex radial motion of a star induced by the presence of companions and is the most successful method to detect exoplanets. If several planets are present, their signals will appear combined in the radial motion of the star, leading to potential misinterpretations of the data. Specifically, two planets in 2:1 resonant orbits can mimic the signal of a single planet in an eccentric orbit. We quantify the implications of this statistical degeneracy for a representative sample of the reported single exoplanets with available data sets, finding that (1) around 35% of the published eccentric one-planet solutions are statistically indistinguishable from planetary systems in 2:1 orbital resonance, (2) another 40% cannot be statistically distinguished from a circular orbital solution, and (3) planets with masses comparable to Earth could be hidden in known orbital solutions of eccentric super-Earths and Neptune mass planets.
- ID:
- ivo://CDS.VizieR/J/A+A/506/491
- Title:
- Eclipsing binary candidates in Corot-IRa01 field
- Short Name:
- J/A+A/506/491
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CoRoT is a pioneering space mission devoted to the analysis of stellar variability and the photometric detection of extrasolar planets. We present the list of planetary transit candidates detected in the first field observed by CoRoT, IRa01, the initial run toward the Galactic anticenter, which lasted for 60 days. We analysed 3898 sources in the coloured bands and 5974 in the monochromatic band. Instrumental noise and stellar variability were taken into account using detrending tools before applying various transit search algorithms.
- ID:
- ivo://CDS.VizieR/J/A+A/557/A119
- Title:
- Eclipsing binary system LL Aquarii
- Short Name:
- J/A+A/557/A119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The eclipsing binary LL Aqr consists of two late-type stars in an eccentric orbit with a period of 20.17d. We use an extensive light curve from the SuperWASP survey augmented by published radial velocities and UBV light curves to measure the physical properties of the system. The primary star has a mass of 1.167+/-0.009M_{sun}_ and a radius of 1.305+/-0.007R_{sun}_. The secondary star is an analogue of the Sun, with a mass and radius of 1.014+/-0.006M_{sun}_ and 0.990+/-0.008R_{sun}_ respectively. The system shows no signs of stellar activity: the upper limit on spot-induced rotational modulation is 3mmag, it is slowly rotating, has not been detected at X-ray wavelengths, and the calcium H and K lines exhibit no emission. Theoretical stellar models provide a good match to its properties for a sub-solar metal abundance of Z=0.008 and an age of 2.5Gyr. Most low-mass eclipsing binary systems are found to have radii larger than expected from theoretical predictions, blamed on tidally-enhanced magnetic fields in these short- period systems. The properties of LL Aqr support this scenario: it exhibits negligible tidal effects, shows no signs of magnetic activity, and matches theoretical models well.
- ID:
- ivo://CDS.VizieR/J/A+A/411/559
- Title:
- Effective temperature for 181 F-K dwarfs
- Short Name:
- J/A+A/411/559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Line depth ratios measured on high resolution (R=42000), high S/N echelle spectra are used for the determination of precise effective temperatures of 181 F, G, K main Sequence stars with about solar metallicity (-0.5<[Fe/H]<+0.5). A set of 105 relations is obtained which rely Teff on ratios of the strengths of lines with high and low excitation potentials, calibrated against previously published precise (1%) temperature estimates. The application range of the calibrations is 4000-6150K (F8V-K7V). The internal error of a single calibration is less than 100K, while the combination of all calibrations for a spectrum of S/N=100 reduces uncertainty to only 5-10K, and for S/N=200 or higher to better than 5K. The zero point of the temperature scale is directly defined from reflection spectra of the Sun with an uncertainty about 1K. The application of this method to investigation of the planet host stars properties is discussed.
- ID:
- ivo://CDS.VizieR/J/AJ/151/17
- Title:
- Eight transiting light curves of WASP-43b
- Short Name:
- J/AJ/151/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Motivated by the previously reported high orbital decay rate of the planet WASP-43b, we have obtained and present eight newly transiting light curves. Together with other data in the literature, we perform a self-consistent timing analysis with data covering a timescale of 1849 epochs. The results give an orbital decay rate dP/dt=-0.02890795+/-0.00772547s/year, which is one order smaller than previous values. This slow decay rate corresponds to a normally assumed theoretical value of the stellar tidal dissipation factor. In addition, through the frequency analysis, the transit timing variations presented here are unlikely to be periodic, but could be signals of a slow orbital decay.
- ID:
- ivo://CDS.VizieR/J/A+A/410/1051
- Title:
- ELODIE survey for northern extra-solar planets. II.
- Short Name:
- J/A+A/410/1051
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Here are the 69 radial-velocity measurements of GJ 777A (HD 190360) used for deriving the orbital solution of this star. These velocities were obtained using the ELODIE echelle spectrograph mounted on the 1.93-m Telescope at Observatoire de Haute-Provence (France) and the AFOE spectrograph mounted on the 1.5-m Telescope at the Fred Lawrence Whipple Observatory (USA).
- ID:
- ivo://CDS.VizieR/J/A+A/414/351
- Title:
- ELODIE survey for northern extrasolar planets III
- Short Name:
- J/A+A/414/351
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present here the radial-velocity measurements for 9 solar-type stars: Ups And (HD 9826), HD 74156, 55 Cnc (HD 75732), 47 UMa (HD 95128), 70 Vir (HD 117176), 14 Her (HD 145675), HD 187123, HD 209458 and 51 Peg (HD 217014). These velocities were obtained using the ELODIE echelle spectrograph mounted on the 1.93-m telescope at the Observatoire de Haute-Provence (France) and the CORALIE echelle spectrograph mounted on the 1.2-m Euler Swiss telescope at the ESO-La Silla Observatory (Chile).