- ID:
- ivo://CDS.VizieR/J/ApJ/783/4
- Title:
- Properties of Kepler multi-planet candidate systems
- Short Name:
- J/ApJ/783/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The planet occurrence rate for multiple stars is important in two aspects. First, almost half of stellar systems in the solar neighborhood are multiple systems. Second, the comparison of the planet occurrence rate for multiple stars to that for single stars sheds light on the influence of stellar multiplicity on planet formation and evolution. We developed a method of distinguishing planet occurrence rates for single and multiple stars. From a sample of 138 bright (K_P_<13.5) Kepler multi-planet candidate systems, we compared the stellar multiplicity rate of these planet host stars to that of field stars. Using dynamical stability analyses and archival Doppler measurements, we find that the stellar multiplicity rate of planet host stars is significantly lower than field stars for semimajor axes less than 20AU, suggesting that planet formation and evolution are suppressed by the presence of a close-in companion star at these separations. The influence of stellar multiplicity at larger separations is uncertain because of search incompleteness due to a limited Doppler observation time baseline and a lack of high-resolution imaging observation. We calculated the planet confidence for the sample of multi-planet candidates and find that the planet confidences for KOI 82.01, KOI 115.01, KOI 282.01, and KOI 1781.02 are higher than 99.7% and thus validate the planetary nature of these four planet candidates. This sample of bright Kepler multi-planet candidates with refined stellar and orbital parameters, planet confidence estimation, and nearby stellar companion identification offers a well-characterized sample for future theoretical and observational study.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/156/213
- Title:
- Properties of N2K stars & new gas giant companions
- Short Name:
- J/AJ/156/213
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The N2K planet search program was designed to exploit the planet-metallicity correlation by searching for gas giant planets orbiting metal-rich stars. Here, we present the radial velocity measurements for 378 N2K target stars that were observed with the HIRES spectrograph at Keck Observatory between 2004 and 2017. With this data set, we announce the discovery of six new gas giant exoplanets: a double-planet system orbiting HD 148164 (Msini of 1.23 and 5.16 M_JUP_) and single planet detections around HD 55696 (Msini=3.87 M_JUP_), HD 98736 (Msini=2.33 M_JUP_), HD 203473 (Msini=7.8 M_JUP_), and HD 211810 (Msini=0.67 M_JUP_). These gas giant companions have orbital semimajor axes between 1.0 and 6.2 au and eccentricities ranging from 0.13 to 0.71. We also report evidence for three gravitationally bound companions with Msini between 20 and 30 M_JUP_, placing them in the mass range of brown dwarfs, around HD 148284, HD 214823, and HD 217850, and four low-mass stellar companions orbiting HD 3404, HD 24505, HD 98630, and HD 103459. In addition, we present updated orbital parameters for 42 previously announced planets. We also report a nondetection of the putative companion HD 73256 b. Finally, we highlight the most promising candidates for direct imaging and astrometric detection, and we find that many hot Jupiters from our sample could be detectable by state-of-the-art telescopes such as Gaia.
- ID:
- ivo://CDS.VizieR/J/AJ/154/228
- Title:
- Properties of transiting planet's host stars
- Short Name:
- J/AJ/154/228
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The properties of a transiting planet's host star are written in its transit light curve. The light curve can reveal the stellar density ({rho}_*_) and the limb-darkening profile in addition to the characteristics of the planet and its orbit. For planets with strong prior constraints on orbital eccentricity, we may measure these stellar properties directly from the light curve; this method promises to aid greatly in the characterization of transiting planet host stars targeted by the upcoming NASA Transiting Exoplanet Survey Satellite mission and any long-period, singly transiting planets discovered in the same systems. Using Bayesian inference, we fit a transit model, including a nonlinear limb-darkening law, to 66 Kepler transiting planet hosts to measure their stellar properties. We present posterior distributions of {rho}*, limb-darkening coefficients, and other system parameters for these stars. We measure densities to within 5% for the majority of our target stars, with the dominant precision-limiting factor being the signal-to-noise ratio of the transits. Of our measured stellar densities, 95% are in 3{sigma} or better agreement with previously published literature values. We make posterior distributions for all of our target Kepler objects of interest available online at 10.5281/zenodo.1028515.
- ID:
- ivo://CDS.VizieR/J/A+A/640/A27
- Title:
- Protoplanetary disk masses in NGC 2024
- Short Name:
- J/A+A/640/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Protoplanetary disks in dense, massive star-forming regions (SFRs) are strongly affected by their environment. How this environmental impact changes over time is an important constraint on disk evolution and external photoevaporation models. We characterized the dust emission from 179 disks in the core of the young (0.5Myr) NGC 2024 cluster. By studying how the disk mass varies within the cluster, and comparing these disks to those in other regions, we determined how external photoevaporation influences disk properties over time. Using the Atacama Large Millimeter/submillimeter Array (ALMA), a 2.9'x2.9' mosaic centered on NGC 2024 FIR 3 was observed at 225GHz with a resolution of 0.25'', or ~100AU. It contains 179 disks identified at IR wavelengths, 7 new disk candidates, and several protostars. Of the disks in the sample, 57 are detected. The overall detection rate is 32+/-4%. Few of the disks are resolved, with the exception of a giant (R=300AU) transition disk. Serendipitously, we observe a millimeter flare from an X-ray bright Young Stellar Object (YSO), and resolve continuum emission from a Class 0 YSO in the FIR 3 core. Two distinct disk populations are present: a more massive one in the east, along the dense molecular ridge hosting the FIR 1-5 YSOs, with a detection rate of 45+/-7%. In the western population, towards IRS 1, only 15+/-4% of disks are detected. NGC 2024 hosts two distinct disk populations. Disks along the dense molecular ridge are young (0.2-0.5Myr) and partly shielded from the FUV radiation of IRS 2b; their masses are similar to isolated 1-3Myr old SFRs. The western population is older and at lower extinctions, and may be affected by external photoevaporation from both IRS 1 and IRS 2b. It is, however, possible these disks had lower masses to begin with.
- ID:
- ivo://CDS.VizieR/J/ApJ/775/45
- Title:
- PTI carbon star angular size survey
- Short Name:
- J/ApJ/775/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report new interferometric angular diameter observations of 41 carbon stars observed with the Palomar Testbed Interferometer. Two of these stars are CH carbon stars and represent the first such measurements of this subtype. Of these, 39 have Yamashita spectral classes and are of sufficiently high quality that we can determine the dependence of effective temperature on spectral type. We find that there is a tendency for the effective temperature to increase with increasing temperature index by ~120K per step, starting at T_eff_=~2500K for C3, y, although there is a large amount of scatter in this relationship. Overall, the median effective temperature of the carbon star sample is 2800+/-270 K and the median linear radius is 360+/-100R_{sun}_. We also find agreement, on average within 15K, with the T_eff_ determinations of Bergeat et al. (J/A+A/369/178) and a refinement of the carbon star angular size prediction based on V & K magnitudes is presented that is good to an rms of 12%. A subsample of our stars have sufficient {u, v} coverage to permit non-spherical modeling of their photospheres, and a general tendency for detection of statistically significant departures from sphericity with increasing interferometric signal-to-noise is seen. The implications of most -and potentially all- carbon stars being non-spherical is considered in the context of surface inhomogeneities and a rotation-mass-loss connection.
- ID:
- ivo://CDS.VizieR/J/A+A/625/A68
- Title:
- Radii and masses of the CARMENES targets
- Short Name:
- J/A+A/625/A68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We determine the radii and masses of 293 nearby, bright M dwarfs of the CARMENES survey. This is the first time that such a large and homogeneous high-resolution (R>80000) spectroscopic survey has been used to derive these fundamental stellar parameters. We derived the radii using Stefan-Boltzmann's law. We obtained the required effective temperatures Teff from a spectral analysis and we obtained the required luminosities L from integrated broadband photometry together with the Gaia DR2 parallaxes. The mass was then determined using a mass-radius relation that we derived from eclipsing binaries known in the literature. We compared this method with three other methods: (1) We calculated the mass from the radius and the surface gravity logg, which was obtained from the same spectral analysis as Teff. (2) We used a widely used infrared mass-magnitude relation. (3) We used a Bayesian approach to infer stellar parameters from the comparison of the absolute magnitudes and colors of our targets with evolutionary models. Between spectral types M0V and M7V our radii cover the range 0.1R_{sun}_<R<0.6R_{sun}_ with an error of 2-3% and our masses cover 0.09M_{sun}_<M<0.6M_{sun}_ with an error of 3-5%. We find good agreement between the masses determined with these different methods for most of our targets. Only the masses of very young objects show discrepancies. This can be well explained with the assumptions that we used for our methods.
- ID:
- ivo://CDS.VizieR/VI/57
- Title:
- Radii of Be star line emitting regions
- Short Name:
- VI/57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This bibliographic catalogue lists radii of line emitting regions around more than 100 Be stars determined from high signal to noise registrations of emission line profiles, listed in nine papers.
- ID:
- ivo://CDS.VizieR/J/ApJ/694/1085
- Title:
- Radii of exoplanet host stars
- Short Name:
- J/ApJ/694/1085
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present interferometric angular sizes for 12 stars with known planetary companions, for comparison with 28 additional main-sequence stars not known to host planets. For all objects we estimate bolometric fluxes and reddenings through spectral-energy distribution (SED) fits, and in conjunction with the angular sizes, measurements of effective temperature. The angular sizes of these stars are sufficiently small that the fundamental resolution limits of our primary instrument, the Palomar Testbed Interferometer, are investigated at the sub-milliarcsecond level and empirically established based upon known performance limits. We demonstrate that the effective temperature scale as a function of dereddened (V-K)0 color is statistically identical for stars with and without planets. Additionally, in an Appendix we provide SED fits for the 166 stars with known planets which have sufficient photometry available in the literature for such fits; this derived "XO-Rad" database includes homogeneous estimates of bolometric flux, reddening, and angular size.
- ID:
- ivo://CDS.VizieR/J/ApJ/799/180
- Title:
- Radii of 430 KOI Earth- to Neptune-sized planets
- Short Name:
- J/ApJ/799/180
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the cumulative catalog of planets detected by the NASA Kepler mission, we reconstruct the intrinsic occurrence of Earth- to Neptune-size (1-4R_{Earth}_) planets and their distributions with radius and orbital period. We analyze 76711 solar-type (0.8<R_*_/R_{sun}_<1.2) stars with 430 planets on 20-200 day orbits, excluding close-in planets that may have been affected by the proximity to the host star. Our analysis considers errors in planet radii and includes an "iterative simulation" technique that does not bin the data. We find a radius distribution that peaks at 2-2.8 Earth radii, with lower numbers of smaller and larger planets. These planets are uniformly distributed with logarithmic period, and the mean number of such planets per star is 0.46+/-0.03. The occurrence is ~0.66 if planets interior to 20 days are included. We estimate the occurrence of Earth-size planets in the "habitable zone" (defined as 1-2 R_{Earth}_, 0.99-1.7AU for solar-twin stars) as 6.4_-1.1_^+3.4^%. Our results largely agree with those of Petigura et al. (2013PNAS..11019273P), although we find a higher occurrence of 2.8-4 Earth-radii planets. The reasons for this excess are the inclusion of errors in planet radius, updated Huber et al. (2014, J/ApJS/211/2) stellar parameters, and also the exclusion of planets that may have been affected by proximity to the host star.
- ID:
- ivo://CDS.VizieR/J/A+A/373/1032
- Title:
- Radio emission from planetary nebulae
- Short Name:
- J/A+A/373/1032
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have analysed the radio fluxes for 264 planetary nebulae for which reliable measurements of fluxes at 1.4 and 5 GHz, and of nebular diameters are available. For many of the investigated nebulae, the optical thickness is important, especially at 1.4 GHz. Simple models like the one specified only by a single optical thickness or spherical, constant density shells do not account satisfactorily for the observations. Also an r^-2^ density distribution is ruled out. A reasonable representation of the observations can be obtained by a two-component model having regions of two different values of optical thickness. We show that the nebular diameters smaller than 10" are uncertain, particularly if they come from photographic plates or Gaussian fitting to the radio profile. While determining the interstellar extinction from an optical to radio flux ratio, caution should be paid regarding optical thickness effects in the radio. We have developed a method for estimating the value of self absorption. At 1.4 GHz self absorption of the flux is usually important and can exceed a factor of 10. At 5 GHz self absorption is negligible for most of the objects, although in some cases it can reach a factor of 2. The Galactic bulge planetary nebulae when used to calibrate the Shklovsky method give a mean nebular mass of 0.14M_{sun}_. The statistical uncertainty of the Shklovsky distances is smaller than a factor of 1.5.
