- ID:
- ivo://CDS.VizieR/J/A+A/604/L4
- Title:
- HAT-P-4 and TYC 2569-744-1 abundances and spectra
- Short Name:
- J/A+A/604/L4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore condensation temperature Tc trends and the Li content in the binary system HAT-P-4, to study the possible chemical signature of planet formation. The star HAT-P-4 hosts a hot Jupiter planet detected by transits, while its stellar companion does not have any detected planets. We derived the fundamental parameters and abundances using the differential method. HAT-P-4 is found to be about 0.1dex more metal rich than its companion; it is enhanced in refractory elements and presents a higher Lithium content. We propose a scenario of a possible rocky planet engulfment in HAT-P-4, which explains the higher metallicity, the higher Li content, and the negative Tc trend we detected.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/155/114
- Title:
- HAT-TR-318-007: a double-lined M dwarf binary
- Short Name:
- J/AJ/155/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery by the HATNet survey of HAT-TR-318-007, a P=3.34395390+/-0.00000020 day period detached double-lined M dwarf binary with total secondary eclipses. We combine radial velocity (RV) measurements from TRES/FLWO 1.5 m and time-series photometry from HATNet, FLWO 1.2 m, BOS 0.8 m, and NASA K2 Campaign 5, to determine the masses and radii of the component stars: M_A_=0.448+/-0.011 M_{sun}_^N^, M_B_=0.2721_-0.0042_^+0.0041^ M_{sun}_^N^, R_A_=0.4548_-0.0036_^+0.0035^ R_{sun}_^N^, and R_B_=0.2913_-0.0024_^+0.0023^ R_{sun}_^N^. We obtained a FIRE/Magellan near-infrared spectrum of the primary star during a total secondary eclipse, and we use this to obtain disentangled spectra of both components. We determine spectral types of ST_A_=M3.71+/-0.69 and ST_B_=M5.01+/-0.73 and effective temperatures of T_eff,A_=3190+/-110 K and T_eff,B_=3100+/-110 K for the primary and secondary star, respectively. We also measure a metallicity of [Fe/H]=+0.298+/-0.080 for the system. We find that the system has a small, but significant, nonzero eccentricity of 0.0136+/-0.0026. The K2 light curve shows a coherent variation at a period of 3.41315_-0.00032_^+0.00030^ days, which is slightly longer than the orbital period, and which we demonstrate comes from the primary star. We interpret this as the rotation period of the primary. We perform a quantitative comparison between the Dartmouth stellar evolution models and the seven systems, including HAT-TR-318-007, that contain M dwarfs with 0.2 M_{sun}_^N^<M<0.5 M_{sun}_^N^, have metallicity measurements, and have masses and radii determined to better than 5% precision. Discrepancies between the predicted and observed masses and radii are found for three of the systems.
- ID:
- ivo://CDS.VizieR/J/ApJ/829/116
- Title:
- H-band spectroscopic analysis of 25 bright M31 GCs
- Short Name:
- J/ApJ/829/116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Chemical abundances are presented for 25 M31 globular clusters (GCs), based on moderately high resolution (R=22500) H-band integrated light (IL) spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE). Infrared (IR) spectra offer lines from new elements, lines of different strengths, and lines at higher excitation potentials compared to the optical. Integrated abundances of C, N, and O are derived from CO, CN, and OH molecular features, while Fe, Na, Mg, Al, Si, K, Ca, and Ti abundances are derived from atomic features. These abundances are compared to previous results from the optical, demonstrating the validity and value of IR IL analyses. The CNO abundances are consistent with typical tip of the red giant branch stellar abundances but are systematically offset from optical Lick index abundances. With a few exceptions, the other abundances agree between the optical and the IR within the 1{sigma} uncertainties. The first integrated K abundances are also presented and demonstrate that K tracks the {alpha} elements. The combination of IR and optical abundances allows better determinations of GC properties and enables probes of the multiple populations in extragalactic GCs. In particular, the integrated effects of the Na/O anticorrelation can be directly examined for the first time.
- ID:
- ivo://CDS.VizieR/J/A+A/635/A4
- Title:
- HCN-to-HNC intensity ratio
- Short Name:
- J/A+A/635/A4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The gas kinetic temperature (TK) determines the physical and chemical evolution of the interstellar medium (ISM). However, obtaining reliable TK estimates usually requires expensive observations including the combination of multi-line analysis and dedicated radiative transfer calculations. This work explores the use of HCN and HNC observations, and particularly the I(HCN)-to-I(HNC) intensity ratio (I(HCN)/I(HNC)) of their J=1-0 lines, as direct probe of the gas kinetic temperature in the molecular ISM. We obtained a new set of large-scale observations of the HCN and HNC (1-0) lines throughout the Integral Shape Filament (ISF) in Orion. In combination with ancillary gas and dust temperature measurements, we find a systematic temperature dependence of the observed I(HCN)-to-I(HNC) intensity ratio throughout our maps. Additional comparisons with chemical models demonstrate that these observed I(HCN)/I(HNC) variations are driven by the effective destruction and isomerization mechanisms of HNC under low-energy barriers. The observed variations of I(HCN)/I(HNC) with TK can be described with a two-part linear function. This empirical calibration is then used to create a temperature map of the entire ISF. Comparisons with similar dust temperature measurements in this cloud, as well as in other regions and galactic surveys, validate this simple technique for obtaining direct estimates of the gas kinetic temperature in a wide range of physical conditions and scales with an optimal working range between 15K<TK<=40K. Both observations and models demonstrate the strong sensitivity of the I(HCN)/I(HNC) ratio to the gas kinetic temperature. Since these lines are easily obtained in observations of local and extragalactic sources, our results highlight the potential use of this observable as new chemical thermometer for the ISM.
- ID:
- ivo://CDS.VizieR/J/MNRAS/417/495
- Title:
- HD 32115 and HD 37594 atmospheric parameters
- Short Name:
- J/MNRAS/417/495
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present detailed parameter determinations of two chemically normal late A-type stars, HD 32115 and HD 37594, to uncover the reasons behind large discrepancies between two previous analyses of these stars performed with a semi-automatic procedure and a 'classical' analysis. Our study is based on high-resolution, high signal-to-noise ratio spectra obtained at the McDonald Observatory. Our method is based on the simultaneous use of all available observables: multicolour photometry, pressure-sensitive magnesium lines, metallic lines and Balmer line profiles. Our final set of fundamental parameters fits, within the error bars, all available observables. It differs from the published results obtained with a semi-automatic procedure.
- ID:
- ivo://CDS.VizieR/J/A+A/592/A83
- Title:
- HD 100546 and TW Hya model abundances
- Short Name:
- J/A+A/592/A83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The composition of planetary solids and gases is largely rooted in the processing of volatile elements in protoplanetary disks. To shed light on the key processes, we carry out a comparative analysis of the gas-phase carbon abundance in two systems with a similar age and disk mass, but different central stars: HD 100546 and TW Hya. We combine our recent detections of C0 in these disks with observations of other carbon reservoirs (CO, C^+^, C_2_H) and gas-mass and warm-gas tracers (HD, O^0^), as well as spatially resolved ALMA observations and the spectral energy distribution. The disks are modelled with the DALI 2D physical-chemical code. Stellar abundances for HD 100546 are derived from archival spectra. Upper limits on HD emission from HD 100546 place an upper limit on the total disk mass of <=0.1M_{sun}_. The gas-phase carbon abundance in the atmosphere of this warm Herbig disk is, at most, moderately depleted compared to the interstellar medium, with Bootis star, with solar abundances of C and O but a strong depletion of rockforming elements. In the gas of the T Tauri disk TW Hya, both C and O are strongly underabundant, with [C]/[H]_gas_=(0.2-5.0)x10^-6^ and C/O>1. We discuss evidence that the gas-phase C and O abundances are high in the warm inner regions of both disks. Our analytical model, including vertical mixing and a grain size distribution, reproduces the observed [C]/[H]_gas_ in the outer disk of TW Hya and allows to make predictions for other systems.
- ID:
- ivo://CDS.VizieR/J/AJ/134/321
- Title:
- H{delta} line in globular clusters
- Short Name:
- J/AJ/134/321
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a cautionary study exploring the reliability of the H{delta} line in the integrated spectra of galaxies for determining galaxy ages. Our database consists of the observed integrated spectra of ~120 early-type galaxies, 7 metal-rich globular clusters in M31 and the Galactic globular cluster 47 Tuc, and the open cluster M67. We have measured H{delta} using index definitions designed to assess contamination from the CN molecule in and around H{delta} by choosing combinations of bandpasses that both avoid and include a region of CN molecular lines redward of H{delta}. We find systematic differences in the ages derived from H{delta} measurements among the various definitions when extracting ages from H{delta} in old stellar populations with enhanced CN bands due to nonsolar abundance ratios. We propose that neighboring CN lines have a strong effect on pseudocontinuum and central bandpass levels. For stellar populations that have nonsolar abundance ratios in C and/or N, population synthesis models that do not account for abundance ratio variations cannot accurately reproduce the CN 4216{AA} band, which leads to a corresponding inaccuracy in reproducing the various H{delta} indices. Hence, caution must be used when extracting galaxy ages from the H{delta} line in old stellar populations with significant nonsolar abundance ratios.
- ID:
- ivo://CDS.VizieR/J/ApJ/632/L131
- Title:
- HD13189 equivalent widths and abundances
- Short Name:
- J/ApJ/632/L131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the abundances of 13 elements in the planetary host HD 13189, a massive giant star.
- ID:
- ivo://CDS.VizieR/J/A+AS/137/227
- Title:
- HD 133029 & HD 192913 elemental abundances
- Short Name:
- J/A+AS/137/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Fine analyses of the silicon stars HD 133029 and HD 192913 are presented using ATLAS9 model atmospheres whose predictions fit the optical region spectrophotometry and H{gamma} profiles and have the same bulk metallicity as the deduced abundances. Both are very He poor stars. The light elements are mostly solar except for silicon, and all the heavier elements, except nickel in HD 133029 which is solar, are greatly overabundant. The iron peak elements are typically 10 times overabundant. SrYZr are of order of 100 times solar. The rare earths are 1000 or more times overabundant.
- ID:
- ivo://CDS.VizieR/J/AJ/159/9
- Title:
- HD 150382 lithium-rich star at the early-AGB stage
- Short Name:
- J/AJ/159/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a lithium-rich giant, HD 150382, a post-red-giant-branch clump star. The atmospheric parameters, the chemical abundances for 17 elements, and the isotopic ratio ^12^C/^13^C were determined using the equivalent width and the spectral synthesis methods. The lithium abundance was determined via spectral synthesis of the Li I resonance doublet at {lambda} 6708 yielding log{epsilon}(Li)_NLTE_=2.55. The excited-state line at {lambda} 6104 also was analyzed. In addition, we have used theoretical evolutionary tracks to determine the mass and luminosity of HD 150382 and compare it with other well-known lithium-rich giants in the literature. Our results show that HD 150382 is a slowly rotating K-giant star having near-solar metallicity. We also show that HD 150382 is not s-process enriched, which is in agreement with its evolutionary status. Finally, based on the abundance results, we study the possible scenarios of the lithium enrichment.