Li abundances for solar twins in the open cluster M67

Carlos, M.; Meléndez, Jorge; Nascimento, J. D. do; Castro, M.

doi:10.1093/mnras/stz3504

Cited by 12 publications

(14 citation statements)

References 52 publications

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“…At the basis of the method is the relationship between the abundances of Li in stellar atmospheres and stellar ages (or masses). This method is supported by limited observational evidence available for metal-rich Galactic open clusters: M67, NGC 752, and Hyades (Castro et al 2016;Carlos et al 2020). As stars evolve away from the main sequence, the growing convective envelope touches the inner layers of a star, in which Li destruction takes place.…”

Section: Abundancesmentioning

confidence: 91%

Weighing stars from birth to death: mass determination methods across the HRD

Serenelli

Weiß

Aerts

et al. 2021

Astron Astrophys Rev

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The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exist a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning with the most direct and model-independent approach using detached eclipsing binaries. We then move to more indirect and model-dependent methods, such as the quite commonly used isochrone or stellar track fitting. The arrival of quantitative asteroseismology has opened a completely new approach to determine stellar masses and to complement and improve the accuracy of other methods. We include methods for different evolutionary stages, from the pre-main sequence to evolved (super)giants and final remnants. For all methods uncertainties and restrictions will be discussed. We provide lists of altogether more than 200 benchmark stars with relative mass accuracies between ½0:3; 2% for the covered mass range of M 2 ½0:1; 16 M , 75% of which are stars burning hydrogen in their core and the other 25% covering all other evolved stages. We close with a recommendation how to combine various methods to arrive at a ''mass-ladder'' for stars.

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Section: Abundancesmentioning

confidence: 91%

Weighing stars from birth to death: mass determination methods across the HRD

Serenelli

Weiß

Aerts

et al. 2021

Astron Astrophys Rev

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“…Este capítulo está baseado nos seguintes artigos desenvolvidos durante o doutorado: Carlos et al (2016Carlos et al ( , 2019Carlos et al ( , 2020.…”

Section: Capítulounclassified

“…Gêmeas solares, para as quais podemos obter idades precisas, podem nos ajudar a entender o principal mecanismo de depleção de Li, seja ele a presença de planetas ou a própria evolução da estrela conforme esta envelhece. Assim, nesse capítulo, apresentamos e discutimos os resultados referentesà análise de três diferentes amostras de gêmeas solares com idades variando entre 0.5 e 9.0 Gano publicados em Carlos et al (2016Carlos et al ( , 2019Carlos et al ( , 2020.…”

Section: Capítulounclassified

“…A segunda amostra, daqui em diante amostra 2, baseada no trabalho de e previamente estudada por dos Santos et al (2017), Spina et al (2018) e Bedell et al (2018, tem resultados discutidos em Carlos et al (2019). Finalmente, a terceira eúltima amostra com análise de A(Li) e publicada em Carlos et al (2020), citada daqui em diante como amostra 3, foi selecionada a partir de uma lista formada por objetos que tenham alta probabilidade de serem membros do aglomerado aberto M67, calculada usando movimentos próprios de Yadav et al (2008), análises espectroscópicas prévias de Pasquini et al (2008), e estudos de velocidade radial de Geller et al (2015). Também foi considerado que as estrelas selecionadas tenham massa aproximadamente igual a 1M , e apresentem estudos de rotação baseados na modulação fotométrica de curvas de luz da missão Kepler K2 (Barnes et al, 2016;Gonzalez, 2016).…”

Section: Amostra E Análiseunclassified

“…A tese de doutorado resultou em quatro artigos como primeira autora, publicados em revistas internacionais arbitradas (Carlos et al, 2016;Carlos et al, 2018;Carlos et al, 2019Carlos et al, , 2020, e outros dois artigos estão sendo preparados como primeira autora, sobre as abundâncias químicas de estrelas anãs K pobres em metais (Capítulo 3) e a nucleossíntese em estrelas de massa intermediária (Capítulo 4). 42,43,44,46,48 Ca/ 40 Ca, 46,47,49,50 Ti/ 48 Ti, 53,54 Cr/ 52 Cr, 54,57,58,60…”

Section: Conclusões E Perspectivasunclassified

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Abundâncias químicas de estrelas anãs G e K e modelos de evolução estelar para [Fe/H]=-1.8 e [Fe/H]=-1.0 com enriquecimento-alpha

Carlos¹

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O estudo de composição química das estrelasé crucial para o entendimento tanto sobre estrutura estelar quanto sobre a história de formação da nossa galáxia.Levando em consideração que o elemento Lié um dos mais importantes traçadores astrofísicos sobre mecanismos de transporte e mistura dentro e abaixo da zona convectiva de estrelas do tipo tardio, concluímos um estudo abrangente sobre depleção de Li em 85 gêmeas solares do campo na vizinhança solar, e mais três gêmeas solares do aglomerado aberto M67. Encontramos uma forte correlação entre depleção de Li e idade estelar, em acordo com modelos não-padrão de evolução estelar. Observamos, também, que o Sol pode ser considerado pobre em Li em comparação a outras gêmeas solares de idades similares (por um fator de ∼ 2σ). Nossos resultados também sugerem que estrelas com os mais baixos conteúdos de Li, para uma dada idade, são acompanhadas de baixos níveis de elementos refratários. Analisamos 8 estrelas anãs K do halo da Galáxia para mais informações sobre a formação dessa componente galáctica, concluindo uma análise química detalhada dos elementos C,

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Lithium depletion and angular momentum transport in solar-type stars

Dumont

Palacios

Charbonnel

et al. 2021

A&A

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Context. Transport processes occurring in the radiative interior of solar-type stars are evidenced by the surface variation of light elements, in particular 7Li, and the evolution of their rotation rates. For the Sun, inversions of helioseismic data indicate that the radial profile of angular velocity in its radiative zone is nearly uniform, which implies the existence of angular momentum transport mechanisms that are efficient over evolutionary timescales. While there are many independent transport models for angular momentum and chemical species, there is a lack of self-consistent theories that permit stellar evolution models to simultaneously match the present-day observations of solar lithium abundances and radial rotation profiles. Aims. We explore how additional transport processes can improve the agreement between evolutionary models of rotating stars and observations for 7Li depletion, the rotation evolution of solar-type stars, and the solar rotation profile. Methods. Models of solar-type stars are computed including atomic diffusion and rotation-induced mixing with the code STAREVOL. We explore different additional transport processes for chemicals and for angular momentum such as penetrative convection, tachocline mixing, and additional turbulence. We constrain the resulting models by simultaneously using the evolution of the surface rotation rate and 7Li abundance in the solar-type stars of open clusters with different ages, and the solar surface and internal rotation profile as inverted from helioseismology when our models reach the age of the Sun. Results. We show the relevance of penetrative convection for the depletion of 7Li in pre-main sequence and early main sequence stars. The rotational dependence of the depth of penetrative convection yields an anti-correlation between the initial rotation rate and 7Li depletion in our models of solar-type stars that is in agreement with the observed trend. Simultaneously, the addition of an ad hoc vertical viscosity νadd leads to efficient transport of angular momentum between the core and the envelope during the main sequence evolution and to solar-type models that match the observed profile of the Sun. We also self-consistently compute for the first time the thickness of the tachocline and find that it is compatible with helioseismic estimations at the age of the Sun, but we highlight that the associated turbulence does not allow the observed 7Li depletion to be reproduced. The main sequence depletion of 7Li in solar-type stars is only reproduced when adding a parametric turbulent mixing below the convective envelope. Conclusions. The need for additional transport processes in stellar evolution models for both chemicals and angular momentum in addition to atomic diffusion, meridional circulation, and turbulent shear is confirmed. We identify the rotational dependence of the penetrative convection as a key process. Two additional and distinct parametric turbulent mixing processes (one for angular momentum and one for chemicals) are required to simultaneously explain the observed surface 7Li depletion and the solar internal rotation profile. We highlight the need of additional constraints for the internal rotation of young solar-type stars and also for the beryllium abundances of open clusters in order to test our predictions.

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Li abundances for solar twins in the open cluster M67

Cited by 12 publications

References 52 publications

Weighing stars from birth to death: mass determination methods across the HRD

Weighing stars from birth to death: mass determination methods across the HRD

Abundâncias químicas de estrelas anãs G e K e modelos de evolução estelar para [Fe/H]=-1.8 e [Fe/H]=-1.0 com enriquecimento-alpha

Lithium depletion and angular momentum transport in solar-type stars

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