- ID:
- ivo://CDS.VizieR/J/A+A/587/A64
- Title:
- Physical properties of giant exoplanets
- Short Name:
- J/A+A/587/A64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- While giant extrasolar planets have been studied for more than two decades now, there are still some open questions as to their dominant formation and migration processes, as well as to their atmospheric evolution in different stellar environments. In this paper, we study a sample of giant transiting exoplanets detected by the Kepler telescope with orbital periods up to 400 days. We first defined a sample of 129 giant-planet candidates that we followed up with the SOPHIE spectrograph (OHP, France) in a 6-year radial velocity campaign. This allowed us to unveil the nature of these candidates and to measure a false-positive rate of 54.6+/-6.5% for giant-planet candidates orbiting within 400 days of period. Based on a sample of confirmed or likely planets, we then derived the occurrence rates of giant planets in different ranges of orbital periods. The overall occurrence rate of giant planets within 400 days is 4.6+/-0.6%. We recovered, for the first time in the Kepler data, the different populations of giant planets reported by radial velocity surveys. Comparing these rates with other yields, we find that the occurrence rate of giant planets is lower only for hot Jupiters but not for the longer-period planets. We also derive a first measurement of the occurrence rate of brown dwarfs in the brown-dwarf desert with a value of 0.29+/-0.17%. Finally, we discuss the physical properties of the giant planets in our sample. We confirm that giant planets receiving moderate irradiation are not inflated, but we find that they are on average smaller than predicted by formation and evolution models. In this regime of low-irradiated giant planets, we find a possible correlation between their bulk density and the iron abundance of the host star, which needs more detections to be confirmed.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/742/L19
- Title:
- Physics of Kepler hot rocky planetary candidates
- Short Name:
- J/ApJ/742/L19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper outlines a simple approach to evaluate the atmospheric composition of hot rocky planets by assuming different types of planetary composition and using corresponding model calculations. To explore hot atmospheres above 1000K, we model the vaporization of silicate magma and estimate the range of atmospheric compositions according to the planet's radius and semi-major axis for the Kepler 2011 February data release. Our results show five atmospheric types for hot, rocky super-Earth atmospheres, strongly dependent on the initial composition and the planet's distance to the star. We provide a simple set of parameters that can be used to evaluate atmospheric compositions for current and future candidates provided by the Kepler mission and other searches.
- ID:
- ivo://CDS.VizieR/J/A+A/633/A13
- Title:
- pi.01 Gru ALMA CO(3-2) data cube
- Short Name:
- J/A+A/633/A13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This study follows up the previous analysis of lower-angular resolution data in which the kinematics and structure of the circumstellar envelope (CSE) around the S-type asymptotic giant branch (AGB) star pi^1^ Gruis were investigated. The AGB star has a known companion (at a separation of ~400AU) which cannot explain the strong deviations from spherical symmetry of the CSE. Recently, hydrodynamic simulations of mass transfer in closer binary systems have successfully reproduced the spiral-shaped CSEs found around a handful of sources. There is growing evidence for an even closer, undetected companion complicating the case of pi^1^ Gruis further. The improved spatial resolution allows for the investigation of the complex circumstellar morphology and the search for imprints on the CSE of the third component. We have observed the ^12^CO J=3-2 line emission from pi^1^ Gruis using both the compact and extended array of Atacama Large Millimeter/submillimeter Array (ALMA). The interferometric data has furthermore been combined with data from the ALMA total power (TP) array. The imaged brightness distribution has been used to constrain a non-local, non-LTE 3D radiative transfer model of the CSE. The high-angular resolution ALMA data have revealed the first example of a source on the AGB where both a faster bipolar outflow and a spiral pattern along the orbital plane can be seen in the gas envelope. The spiral can be traced in the low- to intermediate velocity (13-25km/s) equatorial torus. The largest spiral-arm separation is ~5.5" and consistent with a companion with an orbital period of ~330yrs and a separation of less than 70AU. The kinematics of the bipolar outflow is consistent with it being created during a mass-loss eruption where the mass-loss rate from the system increased by at least a factor of 5 during 10-15yrs. The spiral pattern is the result of an undetected companion. The bipolar outflow is the result of a rather recent mass-loss eruption event.
- ID:
- ivo://CDS.VizieR/J/MNRAS/395/907
- Title:
- PISCO speckle observations in 2007
- Short Name:
- J/MNRAS/395/907
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present relative astrometric measurements of visual binaries made during the first semester of 2007, with the Pupil Interferometry Speckle camera and COronagraph (PISCO) at the 102-cm Zeiss telescope of Brera Astronomical Observatory, in Merate. Our sample contains orbital couples as well as binaries whose motion is still uncertain. We obtained 226 new measurements of 214 objects, with angular separations in the range 0.15-4.5arcsec, and an average accuracy of 0.013arcsec. The mean error on the position angles is. Most of the position angles could be determined without the usual 180{deg} ambiguity with the application of triple-correlation techniques and/or by inspection of the long integration files. We also present the new orbits we have computed for ADS 7871, 7982 and 8128, for which our measurements lead to large residuals and/or for which the revision is justified by the significant number of observations made since the publication of the previous orbit.
- ID:
- ivo://CDS.VizieR/J/MNRAS/367/1170
- Title:
- PISCO speckle observations in 2004
- Short Name:
- J/MNRAS/367/1170
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present relative astrometric measurements of visual binaries taken during the second semester of 2004 with the Pupil Interferometry Speckle camera and Coronagraph (PISCO) at the 1-m Zeiss telescope of the Brera Astronomical Observatory, in Merate, Italy. We performed 207 new observations of 194 objects with angular separations in the range 0.1-4.0" and an accuracy better than ~0.01". Our sample contains orbital couples as well as binaries whose motion is still uncertain. Our purpose is to improve the accuracy of the orbits and constrain the masses of the components.
- ID:
- ivo://CDS.VizieR/J/AN/330/55
- Title:
- PISCO speckle observations in 2006
- Short Name:
- J/AN/330/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present relative astrometric measurements of visual binaries made during the second semester of 2006, with the speckle camera PISCO at the 102cm Zeiss telescope of Brera Astronomical Observatory, in Merate. Our sample contains orbital couples as well as binaries whose motion is still uncertain. We obtained 175 new measurements of 169 objects, with angular separations in the range 0.1"-4.2", and an average accuracy of 0.01". The mean error on the position angles is 0.6{deg}. Most of the position angles could be determined without the usual 180{deg} ambiguity with the application of triple-correlation techniques and/or by inspection of the long integration files.We also present the new orbits we have computed for ADS 11479, 11584 and 16538, for which our measurements lead to large residuals and/or for which the revision was justified by the significant number of observations made since the last orbit computation.
- ID:
- ivo://CDS.VizieR/J/ApJS/222/14
- Title:
- Planetary candidates from 1st yr K2 mission
- Short Name:
- J/ApJS/222/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Kepler Space Telescope is currently searching for planets transiting stars along the ecliptic plane as part of its extended K2 mission. We processed the publicly released data from the first year of K2 observations (Campaigns 0, 1, 2, and 3) and searched for periodic eclipse signals consistent with planetary transits. Out of the 59174 targets that we searched, we detect 234 planetary candidates around 208 stars. These candidates range in size from gas giants to smaller than the Earth, and range in orbital periods from hours to over a month. We conducted initial reconnaissance spectroscopy of 68 of the brighter candidate host stars, and present high-resolution optical spectra for these stars. We make all of our data products, including light curves, spectra, and vetting diagnostics available to users online.
- ID:
- ivo://CDS.VizieR/J/A+A/605/A72
- Title:
- Planetary systems AMD-stability
- Short Name:
- J/A+A/605/A72
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present here in full detail the evolution of the angular momentum deficit (AMD) during collisions as it was described in (Laskar 2000, Physical Review Letters, 84, 3240). Since then, the AMD has been revealed to be a key parameter for the understanding of the outcome of planetary formation models. We define here the AMD-stability criterion that can be easily verified on a newly discovered planetary system. We show how AMD-stability can be used to establish a classification of the multiplanet systems in order to exhibit the planetary systems that are long-term stable because they are AMD-stable, and those that are AMD- unstable which then require some additional dynamical studies to conclude on their stability. The AMD-stability classification is applied to the 131 multiplanet systems from The Extrasolar Planet Encyclopaedia database (exoplanet.eu) for which the orbital elements are sufficiently well known.
- ID:
- ivo://CDS.VizieR/J/ApJS/226/7
- Title:
- Planet candidates discovered using K2's 1st yr
- Short Name:
- J/ApJS/226/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 197 planet candidates discovered using data from the first year of the NASA K2 mission (Campaigns 0-4), along with the results of an intensive program of photometric analyses, stellar spectroscopy, high-resolution imaging, and statistical validation. We distill these candidates into sets of 104 validated planets (57 in multi-planet systems), 30 false positives, and 63 remaining candidates. Our validated systems span a range of properties, with median values of R_P_=2.3R_{Earth}_, P=8.6 days, Teff=5300K, and Kp=12.7mag. Stellar spectroscopy provides precise stellar and planetary parameters for most of these systems. We show that K2 has increased by 30% the number of small planets known to orbit moderately bright stars (1-4R_{Earth}_, Kp=9-13mag). Of particular interest are 76 planets smaller than 2R_{Earth}_, 15 orbiting stars brighter than Kp=11.5mag, 5 receiving Earth-like irradiation levels, and several multi-planet systems-including 4 planets orbiting the M dwarf K2-72 near mean-motion resonances. By quantifying the likelihood that each candidate is a planet we demonstrate that our candidate sample has an overall false positive rate of 15%-30%, with rates substantially lower for small candidates (<2R_{Earth}_) and larger for candidates with radii >8R_{Earth}_ and/or with P<3days. Extrapolation of the current planetary yield suggests that K2 will discover between 500 and 1000 planets in its planned four-year mission, assuming sufficient follow-up resources are available. Efficient observing and analysis, together with an organized and coherent follow-up strategy, are essential for maximizing the efficacy of planet-validation efforts for K2, TESS, and future large-scale surveys.
- ID:
- ivo://CDS.VizieR/J/AJ/155/21
- Title:
- Planet candidates from K2 campaigns 5-8
- Short Name:
- J/AJ/155/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 151 planet candidates orbiting 141 stars from K2 campaigns 5-8 (C5-C8), identified through a systematic search of K2 photometry. In addition, we identify 16 targets as likely eclipsing binaries, based on their light curve morphology. We obtained follow-up optical spectra of 105/141 candidate host stars and 8/16 eclipsing binaries to improve stellar properties and to identify spectroscopic binaries. Importantly, spectroscopy enables measurements of host star radii with ~10% precision, compared to ~40% precision when only broadband photometry is available. The improved stellar radii enable improved planet radii. Our curated catalog of planet candidates provides a starting point for future efforts to confirm and characterize K2 discoveries.