- ID:
- ivo://CDS.VizieR/J/A+A/566/A103
- Title:
- Kepler planet host candidates imaging
- Short Name:
- J/A+A/566/A103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Kepler mission has discovered thousands of planet candidates. Currently, some of them have already been discarded; more than 200 have been confirmed by follow-up observations (most by radial velocity and few by other methods), and several hundreds have been validated. However, the large majority of the candidates are still awaiting for confirmation. Thus, priorities (in terms of the probability of the candidate being a real planet) must be established for subsequent radial velocity observations. The motivation of this work is to provide a set of isolated (good) host candidates to be further tested by other techniques that allow confirmation of the planet. As a complementary goal, we aim to identify close companions of the candidates that could have contaminated the light curve of the planet host due to the large pixel size of the Kepler CCD and its typical PSF of around 6 arcsec. Both goals can also provide robust statistics about the multiplicity of the Kepler hosts. We used the AstraLux North instrument located at the 2.2m telescope in the Calar Alto Observatory (Almeria, Spain) to obtain diffraction-limited images of 174 Kepler objects of interest. A sample of demoted Kepler objects of interest (with rejected planet candidates) is used as a control for comparison of multiplicity statistics. The lucky-imaging technique used in this work is compared to other adaptive optics and speckle imaging observations of Kepler planet host candidates. To that end, we define a new parameter, the blended source confidence level (BSC), to assess the probability of an object to have blended non-detected eclipsing binaries capable of producing the detected transit.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/880/L1
- Title:
- Kepler planet masses, radii and orbital periods
- Short Name:
- J/ApJ/880/L1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Structure in the planet distribution provides an insight into the processes that shape the formation and evolution of planets. The Kepler mission has led to an abundance of statistical discoveries in regards to planetary radius, but the number of observed planets with measured masses is much smaller. By incorporating results from recent mass determination programs, we have discovered a new gap emerging in the planet population for sub-Neptune-mass planets with orbital periods less than 20 days. The gap follows a slope of decreasing mass with increasing orbital period, has a width of a few M_{Earth}_, and is potentially completely devoid of planets. Fitting Gaussian mixture models to the planet population in this region favors a bimodel distribution over a unimodel one with a reduction in Bayesian information criterion of 19.9, highlighting the gap significance. We discuss several processes that could generate such a feature in the planet distribution, including a pileup of planets above the gap region, tidal interactions with the host star, dynamical interactions with the disk, with other planets, or with accreting material during the formation process.
- ID:
- ivo://CDS.VizieR/J/ApJ/787/80
- Title:
- 139 Kepler planets transit time variations
- Short Name:
- J/ApJ/787/80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We extract densities and eccentricities of 139 sub-Jovian planets by analyzing transit time variations (TTVs) obtained by the Kepler mission through Quarter 12. We partially circumvent the degeneracies that plague TTV inversion with the help of an analytical formula for the TTV. From the observed TTV phases, we find that most of these planets have eccentricities of the order of a few percent. More precisely, the rms eccentricity is 0.018_-0.004_^+0.005^, and planets smaller than 2.5 R_{earth}_ are around twice as eccentric as those bigger than 2.5 R_{earth}_. We also find a best-fit density-radius relationship {rho}~3 g/cm^3^x(R/3 R_{earth}_)^-2.3^ for the 56 planets that likely have small eccentricity and hence small statistical correction to their masses. Many planets larger than 2.5 R_{earth}_are less dense than water, implying that their radii are largely set by a massive hydrogen atmosphere.
7544. Kepler Published Planets
- ID:
- ivo://archive.stsci.edu/kepler_published_planets
- Title:
- Kepler Published Planets
- Short Name:
- K Pub Planets
- Date:
- 12 Feb 2020 19:41:28
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- "Kepler Published Planets" is a catalog created from NExScI catalogs listing of published exoplanets found using Kepler. All included metadata is from the published paper.
- ID:
- ivo://CDS.VizieR/J/ApJ/871/174
- Title:
- Kepler rapid rotators and Ks-band excesses
- Short Name:
- J/ApJ/871/174
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tens of thousands of rotation periods have been measured in the Kepler fields, including a substantial fraction of rapid rotators. We use Gaia parallaxes to distinguish photometric binaries (PBs) from single stars on the unevolved lower main sequence, and compare their distribution of rotation properties to those of single stars both with and without Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectroscopic characterization. We find that 59% of stars with 1.5day<P<7day lie 0.3mag above the main sequence, compared with 28% of the full rotation sample. The fraction of stars in the same period range is 1.7{+/-}0.1% of the total sample analyzed for rotation periods. Both the PB fraction and the fraction of rapid rotators are consistent with a population of non-eclipsing short-period binaries inferred from Kepler eclipsing binary data after correcting for inclination. This suggests that the rapid rotators are dominated by tidally synchronized binaries rather than single stars obeying traditional angular momentum evolution. We caution against interpreting rapid rotation in the Kepler field as a signature of youth. Following up on this new sample of 217 candidate tidally synchronized binaries will help further understand tidal processes in stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/4718
- Title:
- Kepler red-clump stars in NGC6819 and NGC6791
- Short Name:
- J/MNRAS/469/4718
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Convective mixing in helium-core-burning (HeCB) stars is one of the outstanding issues in stellar modelling. The precise asteroseismic measurements of gravity-mode period spacing ({Delta}{Pi}_1_) have opened the door to detailed studies of the near-core structure of such stars, which had not been possible before. Here, we provide stringent tests of various core-mixing scenarios against the largely unbiased population of red-clump stars belonging to the old-open clusters monitored by Kepler, and by coupling the updated precise inference on {Delta}{Pi}_1_ in thousands of field stars with spectroscopic constraints. We find that models with moderate overshooting successfully reproduce the range observed of {Delta}{Pi}_1_ in clusters. In particular, we show that there is no evidence for the need to extend the size of the adiabatically stratified core, at least at the beginning of the HeCB phase. This conclusion is based primarily on ensemble studies of {Delta}{Pi}_1_ as a function of mass and metallicity. While {Delta}{Pi}_1_ shows no appreciable dependence on the mass, we have found a clear dependence of {Delta}{Pi}_1_ on metallicity, which is also supported by predictions from models.
- ID:
- ivo://CDS.VizieR/J/A+A/648/A113
- Title:
- Kepler red giants in eclipsing binaries RVs
- Short Name:
- J/A+A/648/A113
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Eclipsing binaries (EBs) are unique targets for measuring accurate stellar properties and constraining stellar evolution models. In particular, it is possible to measure masses and radii at the few percent level for both components of a double-lined spectroscopic EB (SB2-EB). On the one hand, detached EBs hosting at least one star with detectable solar-like oscillations constitute ideal test objects to verify the ability of ensemble asteroseismology to derive stellar properties. On the other hand, the oscillations and surface activity of stars that belong to EBs offer unique information about the evolution of binary systems. This paper builds upon previous works dedicated to red giant stars (RG) in EBs; so far 20 known systems have been discovered by the NASA Kepler mission. We report the discovery of 16 RGs in EBs, which are also from the Kepler data, leading to a total of 36 confirmed RG stars in EBs from the original Kepler mission. This new sample includes three SB2-EBs with oscillations, resulting in a total of 14 known SB2-EBs with an oscillating RG component. This sample also includes six close systems in which the RG display a clear surface activity and complete oscillation suppression. Based on dedicated high-resolution spectroscopic observations (Apache Point Observatory, Observatoire de Haute Provence), we focus on three main aspects. Firstly, from the extended sample of 14 SB2-EBs, we confirm that the simple application of the asteroseismic scaling relations to RGs overestimates masses and radii of RGs by about 15% and 5 %. This bias can be reduced by employing either new asteroseismic reference values for RGs or model-based corrections of the asteroseismic parameters. Secondly, we confirm that close binarity leads to a high level of photometric modulation (up to 10%) and a suppression of solar-like oscillations. In particular, we show that it reduces the lifetime of radial modes by a factor of up to 10. Thirdly, we use our 16 new systems to complement previous observational studies that aimed to constrain tidal dissipation in interacting binaries. We confirm the important role of the equilibrium tide in binary evolution, but we also identify systems with circular orbits despite relatively young ages, which suggests the need to explore complementary tidal dissipation mechanisms in the future. Finally, as a by-product, we report the measurements of mass, radius, and age of three M-dwarf companion stars.
- ID:
- ivo://CDS.VizieR/J/A+A/529/A89
- Title:
- Kepler satellite variability study
- Short Name:
- J/A+A/529/A89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an automated variability analysis of the Kepler public data measured in the first quarter (Q1) of the mission. In total, about 150000 light curves have been analysed to detect stellar variability, and to identify new members of known variability classes. We also focus on the detection of variables present in eclipsing binary systems, given the important constraints on stellar fundamental parameters they can provide. The methodology we use here is based on the automated variability classification pipeline which was previously developed for and applied successfully to the CoRoT exofield database and to the limited subset of a few thousand Kepler asteroseismology light curves. We use a Fourier decomposition of the light curves to describe their variability behaviour and use the resulting parameters to perform a supervised classification. Several improvements have been made, including a separate extractor method to detect the presence of eclipses when other variability is present in the light curves. We also included two new variability classes compared to previous work: variables showing signs of rotational modulation and of activity. Statistics are given on the number of variables and the number of good candidates per class. A comparison is made with results obtained for the CoRoT exoplanet data. We present some special discoveries, including variable stars in eclipsing binary systems. Many new candidate non-radial pulsators are found, mainly Delta Sct and Gamma Dor stars. We have studied those samples in more detail by using 2MASS colours. The full classification results are made available as an online catalogue.
- ID:
- ivo://CDS.VizieR/J/ApJS/197/8
- Title:
- Kepler's candidate multiple transiting planets
- Short Name:
- J/ApJS/197/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- About one-third of the ~1200 transiting planet candidates detected in the first four months of Kepler data are members of multiple candidate systems. There are 115 target stars with two candidate transiting planets, 45 with three, 8 with four, and 1 each with five and six. We characterize the dynamical properties of these candidate multi-planet systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean-motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 resonance. We find that virtually all candidate systems are stable, as tested by numerical integrations that assume a nominal mass-radius relationship. Several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. We provide constraints on the true multiplicity and mutual inclination distribution of the multi-candidate systems, revealing a population of systems with multiple super-Earth-size and Neptune-size planets with low to moderate mutual inclinations.
- ID:
- ivo://CDS.VizieR/J/ApJ/784/45
- Title:
- Kepler's multiple planet candidates. III.
- Short Name:
- J/ApJ/784/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Kepler mission has discovered more than 2500 exoplanet candidates in the first two years of spacecraft data, with approximately 40% of those in candidate multi-planet systems. The high rate of multiplicity combined with the low rate of identified false positives indicates that the multiplanet systems contain very few false positive signals due to other systems not gravitationally bound to the target star. False positives in the multi-planet systems are identified and removed, leaving behind a residual population of candidate multi-planet transiting systems expected to have a false positive rate less than 1%. We present a sample of 340 planetary systems that contain 851 planets that are validated to substantially better than the 99% confidence level; the vast majority of these have not been previously verified as planets. We expect ~two unidentified false positives making our sample of planet very reliable. We present fundamental planetary properties of our sample based on a comprehensive analysis of Kepler light curves, ground-based spectroscopy, and high-resolution imaging. Since we do not require spectroscopy or high-resolution imaging for validation, some of our derived parameters for a planetary system may be systematically incorrect due to dilution from light due to additional stars in the photometric aperture. Nonetheless, our result nearly doubles the number verified exoplanets.