- ID:
- ivo://CDS.VizieR/J/AJ/153/136
- Title:
- Planets and their host stars with Gaia parallaxes
- Short Name:
- J/AJ/153/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present empirical measurements of the radii of 116 stars that host transiting planets. These radii are determined using only direct observables - the bolometric flux at Earth, the effective temperature, and the parallax provided by the Gaia first data release - and thus are virtually model independent, with extinction being the only free parameter. We also determine each star's mass using our newly determined radius and the stellar density, a virtually model independent quantity itself from previously published transit analyses. These stellar radii and masses are in turn used to redetermine the transiting-planet radii and masses, again using only direct observables. The median uncertainties on the stellar radii and masses are 8% and 30%, respectively, and the resulting uncertainties on the planet radii and masses are 9% and 22%, respectively. These accuracies are generally larger than previously published model-dependent precisions of 5% and 6% on the planet radii and masses, respectively, but the newly determined values are purely empirical. We additionally report radii for 242 stars hosting radial-velocity (non-transiting) planets, with a median achieved accuracy of ~2%. Using our empirical stellar masses we verify that the majority of putative "retired A stars" in the sample are indeed more massive than ~1.2 M_{sun}_. Most importantly, the bolometric fluxes and angular radii reported here for a total of 498 planet host stars-with median accuracies of 1.7% and 1.8%, respectively-serve as a fundamental data set to permit the re-determination of transiting-planet radii and masses with the Gaia second data release to ~3% and ~5% accuracy, better than currently published precisions, and determined in an entirely empirical fashion.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/155/136
- Title:
- Planets orbiting bright stars in K2 campaigns 0-10
- Short Name:
- J/AJ/155/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since 2014, NASA's K2 mission has observed large portions of the ecliptic plane in search of transiting planets and has detected hundreds of planet candidates. With observations planned until at least early 2018, K2 will continue to identify more planet candidates. We present here 275 planet candidates observed during Campaigns 0-10 of the K2 mission that are orbiting stars brighter than 13 mag (in Kepler band) and for which we have obtained high-resolution spectra (R=44000). These candidates are analyzed using the vespa package in order to calculate their false-positive probabilities (FPP). We find that 149 candidates are validated with an FPP lower than 0.1%, 39 of which were previously only candidates and 56 of which were previously undetected. The processes of data reduction, candidate identification, and statistical validation are described, and the demographics of the candidates and newly validated planets are explored. We show tentative evidence of a gap in the planet radius distribution of our candidate sample. Comparing our sample to the Kepler candidate sample investigated by Fulton et al. (2017, J/AJ/154/109), we conclude that more planets are required to quantitatively confirm the gap with K2 candidates or validated planets. This work, in addition to increasing the population of validated K2 planets by nearly 50% and providing new targets for follow-up observations, will also serve as a framework for validating candidates from upcoming K2 campaigns and the Transiting Exoplanet Survey Satellite, expected to launch in 2018.
- ID:
- ivo://CDS.VizieR/J/ApJ/697/544
- Title:
- Planets orbiting metal-poor dwarfs. II.
- Short Name:
- J/ApJ/697/544
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of three years of precision radial velocity (RV) measurements of 160 metal-poor stars observed with HIRES on the Keck 1 telescope. We report on variability and long-term velocity trends for each star in our sample. We identify several long-term, low-amplitude RV variables worthy of followup with direct imaging techniques. We place lower limits on the detectable companion mass as a function of orbital period. Our survey would have detected, with a 99.5% confidence level, over 95% of all companions on low-eccentricity orbits with velocity semiamplitude K>~100m/s, or M_p_sini>~3.0M_J_(P/yr)^(1/3)^, for orbital periods P<~3yr. None of the stars in our sample exhibits RV variations compatible with the presence of Jovian planets with periods shorter than the survey duration.
- ID:
- ivo://CDS.VizieR/J/ApJ/855/107
- Title:
- PMAS Integral-field SN hosts COmpilation (PISCO)
- Short Name:
- J/ApJ/855/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the PMAS/PPak Integral-field Supernova hosts COmpilation (PISCO), which comprises integral field spectroscopy (IFS) of 232 supernova (SN) host galaxies that hosted 272 SNe, observed over several semesters with the 3.5m telescope at the Calar Alto Observatory (CAHA). PISCO is the largest collection of SN host galaxies observed with wide-field IFS, totaling 466347 individual spectra covering a typical spatial resolution of ~380pc. Focused studies regarding specific SN Ia-related topics will be published elsewhere; this paper aims to present the properties of the SN environments, using stellar population (SP) synthesis, and the gas-phase interstellar medium, providing additional results separating stripped-envelope SNe into their subtypes. With 11270 HII regions detected in all galaxies, we present for the first time a statistical analysis of HII regions, which puts HII regions that have hosted SNe in context with all other star-forming clumps within their galaxies. SNe Ic are associated with environments that are more metal-rich and have higher EW(H{alpha}) and higher star formation rate within their host galaxies than the mean of all HII regions detected within each host. This in contrast to SNe IIb, which occur in environments that are very different compared to other core-collapse SNe types. We find two clear components of young and old SPs at SNe IIn locations. We find that SNe II fast decliners tend to explode at locations where the {Sigma}SFR is more intense. Finally, we outline how a future dedicated IFS survey of galaxies in parallel to an untargeted SN search would overcome the biases in current environmental studies.
1095. PN abundances
- ID:
- ivo://CDS.VizieR/J/A+AS/126/297
- Title:
- PN abundances
- Short Name:
- J/A+AS/126/297
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Abundance determinations of about 110 planetary nebulae, which are likely to be in the Galactic Bulge are presented. Plasma diagnostics have been performed by making use of the available forbidden line ratios combined with radio continuum measurements. Chemical abundances of He, O, N, Ne, S, Ar, and Cl are then derived by employing theoretical nebular models as interpolation devices in establishing the ionization correction factors (ICFs) used to estimate the distribution of atoms among unobserved ionization stages. The overall agreement between the results derived by using the model-ICFs and those obtained from the theoretical models is reasonably good. The uncertainties related to the total abundances show a clear dependence on the level of excitation. In most cases, the abundances of chlorine can be derived only in objects with a relatively high Cl-abundance. Contrary to the conclusion previously drawn by Webster (1988MNRAS.230..377W), we found the excitation classes are not uniformly distributed. A clear peak at about classes 5 and 6 is noticed. The distribution is shifted toward a lower excitation range with respect to that of the nearby nebulae, reflecting the difference in the central star temperature distribution between the two samples.
- ID:
- ivo://CDS.VizieR/J/ApJS/171/146
- Title:
- Population synthesis in the blue. IV
- Short Name:
- J/ApJS/171/146
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new set of model predictions for 16 Lick absorption line indices from H{delta} through Fe5335 and UBV colors for single stellar populations with ages ranging between 1 and 15Gyr, [Fe/H] ranging from -1.3 to +0.3, and variable abundance ratios. The models are based on accurate stellar parameters for the Jones library stars and a new set of fitting functions describing the behavior of line indices as a function of effective temperature, surface gravity, and iron abundance. The abundances of several key elements in the library stars have been obtained from the literature in order to characterize the abundance pattern of the stellar library, thus allowing us to produce model predictions for any set of abundance ratios desired. We develop a method to estimate mean ages and abundances of iron, carbon, nitrogen, magnesium, and calcium that explores the sensitivity of the various indices modeled to those parameters. The models are compared to high-S/N data for Galactic clusters spanning the range of ages, metallicities, and abundance patterns of interest. Essentially all line indices are matched when the known cluster parameters are adopted as input. Comparing the models to high-quality data for galaxies in the nearby universe, we reproduce previous results regarding the enhancement of light elements and the spread in the mean luminosity-weighted ages of early-type galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/600/A104
- Title:
- Potassium abundance in 3 globular clusters
- Short Name:
- J/A+A/600/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derived Potassium abundances in red giant branch stars in the Galactic globular clusters NGC 104 (144 stars), NGC 6752 (134 stars) and NGC 6809 (151 stars) using high-resolution spectra collected with FLAMES at the ESO - Very Large Telescope. In the considered samples we do not find significant intrinsic spreads in [K/Fe] (confirming the previous findings by Carretta et al.), at variance with the cases of the massive clusters NGC 2419 and NGC 2808. Additionally, marginally significant [K/Fe]-[O/Fe] anti-correlations are found in NGC 104 and NGC 6809, and [K/Fe]-[Na/Fe] correlations are found in NGC 104 and NGC 6752. No evidence of [K/Fe]-[Mg/Fe] anti-correlation are found. The results of our analysis are consistent with a scenario in which the process leading to the multi-populations in globular clusters implies also enrichment in the K abundance, the amplitude of the associated [K/Fe] enhancement becoming measurable only in stars showing the most extreme effects of O and Mg depletion. Stars enhanced in [K/Fe] have been found so far only in clusters harbouring some Mg-poor stars, while the other globulars, without a Mg-poor sub-population, show small or null [K/Fe] spreads.
- ID:
- ivo://CDS.VizieR/J/ApJ/769/40
- Title:
- Potassium abundance in red giants of GCs
- Short Name:
- J/ApJ/769/40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Two independent studies recently uncovered two distinct populations among giants in the distant, massive globular cluster (GC) NGC 2419. One of these populations has normal magnesium (Mg) and potassium (K) abundances for halo stars: enhanced Mg and roughly solar K. The other population has extremely depleted Mg and very enhanced K. To better anchor the peculiar NGC 2419 chemical composition, we have investigated the behavior of K in a few red giant branch stars in NGC 6752, NGC 6121, NGC 1904, and {omega} Cen. To verify that the high K abundances are intrinsic and not due to some atmospheric features in giants, we also derived K abundances in less evolved turn-off and subgiant stars of clusters 47 Tuc, NGC 6752, NGC 6397, and NGC 7099. We normalized the K abundance as a function of the cluster metallicity using 21 field stars analyzed in a homogeneous manner. For all GCs of our sample, the stars lie in the K-Mg abundance plane on the same locus occupied by the Mg-normal population in NGC 2419 and by field stars. This holds for both giants and less-evolved stars. At present, NGC 2419 seems unique among GCs.
- ID:
- ivo://CDS.VizieR/J/AJ/156/142
- Title:
- Precision cluster abund. for APOGEE using SDSS DR14
- Short Name:
- J/AJ/156/142
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to produce a comprehensive, uniform, infrared-based spectroscopic data set for hundreds of open clusters, and to constrain key Galactic dynamical and chemical parameters from this sample. This second contribution from the OCCAM survey presents analysis of 259 member stars with [Fe/H] determinations in 19 open clusters, using Sloan Digital Sky Survey Data Release 14 (SDSS/DR14) data from the Apache Point Observatory Galactic Evolution Experiment and ESA Gaia. This analysis, which includes clusters with R_GC_ ranging from 7 to 13 kpc, measures an [Fe/H] gradient of -0.061+/-0.004 dex/kpc. We also confirm evidence of a significant positive gradient in the {alpha}-elements ([O/Fe], [Mg/Fe], and [Si/Fe]) and present evidence for a significant negative gradient in iron-peak elements ([Mn/Fe] and [Ni/Fe]).
- ID:
- ivo://CDS.VizieR/J/ApJ/715/1050
- Title:
- Predicted abundances for extrasolar planets. I.
- Short Name:
- J/ApJ/715/1050
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extrasolar planet host stars have been found to be enriched in key planet-building elements. These enrichments have the potential to drastically alter the composition of material available for terrestrial planet formation. Here, we report on the combination of dynamical models of late-stage terrestrial planet formation within known extrasolar planetary systems with chemical equilibrium models of the composition of solid material within the disk. This allows us to determine the bulk elemental composition of simulated extrasolar terrestrial planets. A wide variety of resulting planetary compositions are found, ranging from those that are essentially "Earth like", containing metallic Fe and Mg silicates, to those that are dominated by graphite and SiC. This shows that a diverse range of terrestrial planets may exist within extrasolar planetary systems.
