Accurate and homogeneous abundance patterns in solar-type stars of the solar neighbourhood: a chemo-chronological analysis

Silva, R. da; Mello, G. F. Porto de; Milone, A.; Silva, L. da; Ribeiro, L.S.; Rocha-Pinto, Helio J.

doi:10.1051/0004-6361/201118751

Cited by 92 publications

(82 citation statements)

References 61 publications

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“…Barium stars are C-rich (e.g., Barbuy et al 1992), and it is therefore very unlikely that this phenomenon plays a significant role in our sample. The Ba excess we occasionally observe may instead be attributable to a young age, A119, page 16 of 20 as found in field dwarfs of the solar neighbourhood or members of open clusters (e.g., Bensby et al 2007;D'Orazi et al 2009;da Silva et al 2012). In this respect, it may be regarded as significant that high abundances are found in the young, massive star HD 50890 and in the likely members of NGC 6633 with an estimated age in the range 450-575 Myrs according to Smiljanic et al (2009) andvan Leeuwen (2009).…”

Section: Discussion Of Some Key Observational Resultsmentioning

confidence: 76%

Atmospheric parameters and chemical properties of red giants in the CoRoT asteroseismology fields

Morel

Miglio

Lagarde

et al. 2014

A&A

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A precise characterisation of the red giants in the seismology fields of the CoRoT satellite is a prerequisite for further in-depth seismic modelling. High-resolution FEROS and HARPS spectra were obtained as part of the ground-based follow-up campaigns for 19 targets holding great asteroseismic potential. These data are used to accurately estimate their fundamental parameters and the abundances of 16 chemical species in a self-consistent manner. Some powerful probes of mixing are investigated (the Li and CNO abundances, as well as the carbon isotopic ratio in a few cases). The information provided by the spectroscopic and seismic data is combined to provide more accurate physical parameters and abundances. The stars in our sample follow the general abundance trends as a function of the metallicity observed in stars of the Galactic disk. After an allowance is made for the chemical evolution of the interstellar medium, the observational signature of internal mixing phenomena is revealed through the detection at the stellar surface of the products of the CN cycle. A contamination by NeNa-cycled material in the most massive stars is also discussed. With the asteroseismic constraints, these data will pave the way for a detailed theoretical investigation of the physical processes responsible for the transport of chemical elements in evolved, low-and intermediate-mass stars.

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Section: Discussion Of Some Key Observational Resultsmentioning

confidence: 76%

Atmospheric parameters and chemical properties of red giants in the CoRoT asteroseismology fields

Morel

Miglio

Lagarde

et al. 2014

A&A

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“…This is plotted in Figure 3. Also plotted in the same figure is the exact same analysis, but using the temperature estimates of GJ 504 from instead; note that all other values are kept as in da Silva et al (2012). This comparison immediately illuminates one of the considerable uncertainties related to isochronal analysis, which is uncertainties in the temperature scaling.…”

Section: Isochronesmentioning

confidence: 80%

“…This comparison immediately illuminates one of the considerable uncertainties related to isochronal analysis, which is uncertainties in the temperature scaling. The two temperature estimates in and da Silva et al (2012) are inconsistent within their quoted error bars, implying that neither error estimate should be trusted when translating this into an error on the age from the isochronal comparison. Moreover, we find that while the temperature estimate of da Silva et al (2012) gives the aforementioned age of ∼3 Gyr and is inconsistent with 500 Myr ages, the temperature estimate of is fully consistent with these younger ages, and inconsistent with the ∼3 Gyr age.…”

Section: Isochronesmentioning

confidence: 94%

“…Finally, it can be noted that the existence of a star with such a short rotation period as GJ 504 (∼3 days) would be unprecedented at the Gyr scale ages predicted by some isochrone analyses, such as da Silva et al (2012). Indeed, although Reiners & Giampapa (2009) found an unusually rapid rotator in the ∼4 Gyr old M67 cluster, it has a rotation of approximately half the solar rotation rate (P ∼ 30 days), which is significantly slower than the rotation of GJ 504.…”

Section: Isochronesmentioning

confidence: 95%

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Direct Imaging of a Cold Jovian Exoplanet in Orbit Around the Sun-Like Star Gj 504

Kuzuhara

Tamura

Kudo

et al. 2013

ApJ

222

170

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Direct Imaging of a Cold Jovian Exoplanet in Orbit around the Sun-like Star GJ 504Kuzuhara, M.; et al., [Unknown]; Thalmann, C.D. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Download date: 13 May 2018The Astrophysical Journal, 774:11 (18pp) ABSTRACT Several exoplanets have recently been imaged at wide separations of >10 AU from their parent stars. These span a limited range of ages (<50 Myr) and atmospheric properties, with temperatures of 800-1800 K and very red colors (J − H > 0.5 mag), implying thick cloud covers. Furthermore, substantial model uncertainties exist at these young ages due to the unknown initial conditions at formation, which can lead to an order of magnitude of uncertainty in the modeled planet mass. Here, we report the direct-imaging discovery of a Jovian exoplanet around the Sun-like star GJ 504, detected as part of the SEEDS survey. The system is older than all other known directly imaged planets; as a result, its estimated mass remains in the planetary regime independent of uncertainties related to choices of initial conditions in the exoplanet modeling. Using the most common exoplanet cooling model, and given the system age of 160 +350 −60 Myr, GJ 504b has an estimated mass of 4 +4.5 −1.0 Jupiter masses, among the lowest of directly imaged planets. Its projected separation of 43.5 AU exceeds the typical outer boundary of ∼30 AU predicted for the core accretion mechanism. GJ 504b is also significantly cooler (510 +30 −20 K) and has a bluer color (J − H = −0.23 mag) than previously imaged exoplanets, suggesting a largely cloud-free atmosphere accessible to spectroscopic characterization. Thus, it has the potential of providing novel insights into the origins of giant planets as well as their atmospheric properties.

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“…As a result of the possibly significantly different age of HD 42618 compared to the Sun, one might expect subtle differences in its abundance pattern because of the different relative proportion of Type Ia/II supernovae yields and the various amounts of material lost by stellar winds from asymptotic giant branch (AGB) and massive stars along the history of the Galaxy. Tentative (based on data for a dozen stars) relations between the stellar ages and the abundances relative to iron have recently been proposed for nearby, young dwarfs of the thin disk 5 by da Silva et al (2012). However, the abundance pattern of HD 42618 appears to be very close to solar (among the elements with a determined uncertainty, magnesium is the most discrepant one but by only 2.5σ; Fig.…”

Section: Discussionmentioning

confidence: 97%

Abundance study of the two solar-analogue CoRoT targets HD 42618 and HD 43587 from HARPS spectroscopy

Morel

Rainer

Poretti

et al. 2013

A&A

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We present a detailed abundance study based on spectroscopic data obtained with HARPS of two solar-analogue main targets for the asteroseismology programme of the CoRoT satellite: HD 42618 and HD 43587. The atmospheric parameters and chemical composition are accurately determined through a fully differential analysis with respect to the Sun observed with the same instrumental set-up. Several sources of systematic errors largely cancel out with this approach, which allows us to narrow down the 1-σ error bars to typically 20 K in effective temperature, 0.04 dex in surface gravity, and less than 0.05 dex in the elemental abundances. Although HD 42618 fulfils many requirements for being classified as a solar twin, its slight deficiency in metals and its possibly younger age indicate that, strictly speaking, it does not belong to this class of objects. On the other hand, HD 43587 is slightly more massive and evolved. In addition, marked differences are found in the amount of lithium present in the photospheres of these two stars, which might reveal different mixing properties in their interiors. These results will put tight constraints on the forthcoming theoretical modelling of their solar-like oscillations and contribute to increase our knowledge of the fundamental parameters and internal structure of stars similar to our Sun.

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Accurate and homogeneous abundance patterns in solar-type stars of the solar neighbourhood: a chemo-chronological analysis

Cited by 92 publications

References 61 publications

Atmospheric parameters and chemical properties of red giants in the CoRoT asteroseismology fields

Atmospheric parameters and chemical properties of red giants in the CoRoT asteroseismology fields

Direct Imaging of a Cold Jovian Exoplanet in Orbit Around the Sun-Like Star Gj 504

Abundance study of the two solar-analogue CoRoT targets HD 42618 and HD 43587 from HARPS spectroscopy

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