New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s)

Casagrande, Luca; Schönrich, Ralph; Asplund, Martin; Cassisi, S.; Ramírez, Iván; Meléndez, Jorge; Bensby, T.; Feltzing, Sofia

doi:10.1051/0004-6361/201016276

Cited by 830 publications

(1,197 citation statements)

References 137 publications

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“…We point out that the error bars result from the straight propagation from the seismic and luminosity observations; any additional errors due to physics are not taken into account. We can also deduce the effective temperature of the two stars from the luminosities and seismic radii as T eff,A = 6080 ± 155 K and T eff,B = 5900 ± 159 K. This value for Star A is in agreement with the measurements of Casagrande et al (2011).…”

Section: Masses and Radii From Scaling Relationssupporting

confidence: 77%

“…The effective temperature and metallicity constraints used in the modelling were chosen according to the values obtained from colour calibrations by Casagrande et al (2011). All values in the table are derived from photometry and spectroscopy but not from asteroseismology.…”

Section: From the Literaturementioning

confidence: 99%

“…The corresponding luminosity is L B /L = 1.85 ± 0.22 2 . Casagrande et al (2011) provided an age of 3.19 +0.64 −1.10 Gyr and a primary mass of 1.35 +0.13 −0.07 M using the BaSTI 3 stellar models. They also gave an age of 2.93 +1.15 −0.38 Gyr and a primary mass of 1.41 +0.07 −0.13 M using the PADOVA 4 stellar models.…”

Section: From the Literaturementioning

confidence: 99%

“…For Star A, we used the frequency data, photometric observations from Casagrande et al (2011) and luminosity derived in Sect. 2.1.…”

Section: Free Model Mode Frequencies and Analytical Surface Correctimentioning

confidence: 99%

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A seismic and gravitationally bound double star observed byKepler

Appourchaux

Antia

Ball

et al. 2015

A&A

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Context. Solar-like oscillations have been observed by Kepler and CoRoT in many solar-type stars, thereby providing a way to probe stars using asteroseismology. Aims. The derivation of stellar parameters has usually been done with single stars. The aim of the paper is to derive the stellar parameters of a double-star system (HIP 93511), for which an interferometric orbit has been observed along with asteroseismic measurements. Methods. We used a time series of nearly two years of data for the double star to detect the two oscillation-mode envelopes that appear in the power spectrum. Using a new scaling relation based on luminosity, we derived the radius and mass of each star. We derived the age of each star using two proxies: one based upon the large frequency separation and a new one based upon the small frequency separation. Using stellar modelling, the mode frequencies allowed us to derive the radius, the mass, and the age of each component. In addition, speckle interferometry performed since 2006 has enabled us to recover the orbit of the system and the total mass of the system. Results. From the determination of the orbit, the total mass of the system is 2.34 +0.45 −0.33 M . The total seismic mass using scaling relations is 2.47 ± 0.07 M . The seismic age derived using the new proxy based upon the small frequency separation is 3.5 ± 0.3 Gyr. Based on stellar modelling, the mean common age of the system is 2.7-3.9 Gyr. The mean total seismic mass of the system is 2.34-2.53 M consistent with what we determined independently with the orbit. The stellar models provide the mean radius, mass, and age of the stars as R A = 1.82−1.87 R , M A = 1.25−1.39 M , Age A = 2.6-3.5 Gyr; R B = 1.22−1.25 R , M B = 1.08−1.14 M , Age B = 3.35-4.21 Gyr. The models provide two sets of values for Star A: [1.25-1.27] M and [1.34-1.39] M . We detect a convective core in Star A, while Star B does not have any. For the metallicity of the binary system of Z ≈ 0.02, we set the limit between stars having a convective core in the range [1.14-1.25] M .

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Section: Masses and Radii From Scaling Relationssupporting

confidence: 77%

Section: From the Literaturementioning

confidence: 99%

Section: From the Literaturementioning

confidence: 99%

“…For Star A, we used the frequency data, photometric observations from Casagrande et al (2011) and luminosity derived in Sect. 2.1.…”

Section: Free Model Mode Frequencies and Analytical Surface Correctimentioning

confidence: 99%

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A seismic and gravitationally bound double star observed byKepler

Appourchaux

Antia

Ball

et al. 2015

A&A

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“…A specific star may appear more than once but with different data, thus leading to a different object. As described in BJ15, we use GCS (G), RAVE (R), Pulkovo (P) to denote the catalog of objects with radial velocity obtained by crossmatching the revised Hipparcos catalog (van Leeuwen 2007) with the Geneva-Copenhagen survey data by (Casagrande et al 2011), with the Pulkovo catalogue (Gontcharov 2006), and with Rave-DR4 (Kordopatis et al 2013), respectively. We also use data from the XHIP (X) catalog (Anderson & Francis 2012) and the XHIP catalog adapted by (Dybczyński & Berski 2015) (D).…”

Section: Datamentioning

confidence: 99%

Finding the imprints of stellar encounters in long-period comets

Feng

Bailer‐Jones

2015

Mon. Not. R. Astron. Soc.

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The solar system's Oort cloud can be perturbed by the Galactic tide and by individual passing stars. These perturbations can inject Oort cloud objects into the inner parts of the solar system, where they may be observed as the long-period comets (periods longer than 200 years). Using dynamical simulations of the Oort cloud under the perturbing effects of the tide and 61 known stellar encounters, we investigate the link between long-period comets and encounters. We find that past encounters were responsible for injecting at least 5% of the currently known long-period comets. This is a lower limit due to the incompleteness of known encounters. Although the Galactic tide seems to play the dominant role in producing the observed long-period comets, the non-uniform longitude distribution of the cometary perihelia suggests the existence of strong -but as yet unidentified -stellar encounters or other impulses. The strongest individual future and past encounters are probably HIP 89825 (Gliese 710) and HIP 14473, which contribute at most 8% and 6% to the total flux of long-period comets, respectively. Our results show that the strength of an encounter can be approximated well by a simple proxy, which will be convenient for quickly identifying significant encounters in large data sets. Our analysis also indicates a smaller population of the Oort cloud than is usually assumed, which would bring the mass of the solar nebula into line with planet formation theories.

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Full metal bracket: A calibration of infrared and optical spectroscopic metallicities of M dwarfs over 1.5 dex

et al. 2013

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The determination of metallicities in late-type stars is particularly difficult because their cool atmospheres enable the formation of complex molecules. Instead, most studies use wide binaries that include a solar-type primary and an M dwarf companion. However, most previous studies utilize only a small number (15-25) of binaries, limiting the effective range of their calibrations. We present our observations and analysis of a sample of 105 FGK-M wide binary systems with metallicities of −1.04 < [Fe/H] < +0.56 and companion spectral types from K5.5 to M6. We obtain moderate resolution (1300 < R < 2000) visible and near-infrared spectra for each late-type companion, and high-resolution spectra for the 44 primary stars that lack published metallicities. We use our sample to determine, empirically, which spectral features are best correlated with the metallicity of the primary. We find over 80 features in K and M dwarf visible and near-infrared spectra that are useful for predicting metallicity. We use a subset of these features to derive metallicity calibrations for different wavelength regimes, and show that it is possible to get metallicities reliable to < 0.10 dex using either visible, J, H, or K band spectra, however, when using visible spectra this requires the use of different calibrations for early-type (K5.5 to M2) and late-type (M2 to M6) dwarfs.

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New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s)

Cited by 830 publications

References 137 publications

A seismic and gravitationally bound double star observed byKepler

A seismic and gravitationally bound double star observed byKepler

Finding the imprints of stellar encounters in long-period comets

Full metal bracket: A calibration of infrared and optical spectroscopic metallicities of M dwarfs over 1.5 dex

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