Chemical Evolution of the Orion Association. III. The Lithium Abundance of F and G Stars

1995 ◽  
Vol 452 ◽  
pp. 634 ◽  
Author(s):  
Katia Cunha ◽  
Verne V. Smith ◽  
David L. Lambert
Keyword(s):  
Chemical Evolution ◽  
Lithium Abundance ◽  
Orion Association

Chemical Evolution of the Orion Association. IV. The Oxygen and Iron Abundances of F and G Stars

1998 ◽  
Vol 493 (1) ◽  
pp. 195-205 ◽  
Author(s):  
Katia Cunha ◽  
Verne V. Smith ◽  
David L. Lambert
Keyword(s):  
Chemical Evolution ◽  
Orion Association

scholarly journals Chemical composition of stars with massive planets*

2021 ◽  
Author(s):  
T Mishenina ◽  
N Basak ◽  
V Adibekyan ◽  
C Soubiran ◽  
V Kovtyukh
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Chemical Evolution ◽  
Planet Formation ◽  
Galactic Chemical Evolution ◽  
Lithium Abundance ◽  
Mean Values ◽  
Planetary Mass ◽  
Iron Abundance ◽  
The Mean

Abstract Stellar parameters of 25 planet-hosting stars and abundances of Li, C, O, Na, Mg, Al, S, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Zn, Y, Zr, Ba, Ce, Pr, Nd, Sm and Eu, were studied based on homogeneous high resolution spectra and uniform techniques. The iron abundance [Fe/H] and key elements (Li, C, O, Mg, Si) indicative of the planet formation, as well as the dependencies of [El/Fe] on Tcond, were analyzed. The iron abundances determined in our sample stars with detected massive planets range within –0.3 < [Fe/H] < 0.4. The behaviour of [C/Fe], [O/Fe], [Mg/Fe] and [Si/Fe] relative to [Fe/H] is consistent with the Galactic Chemical Evolution trends. The mean values of C/O and [C/O] are <C/O> = 0.48 ±0.07 and <[C/O]> = –0.07 ±0.07, which are slightly lower than solar ones. The Mg/Si ratios range from 0.83 to 0.95 for four stars in our sample and from 1.0 to 1.86 for the remaining 21 stars. Various slopes of [El/Fe] vs. Tcond were found. The dependencies of the planetary mass on metallicity, the lithium abundance, the C/O and Mg/Si ratios, and also on the [El/Fe]–Tcond slopes were considered.

scholarly journals Explaining the decrease in ISM lithium at super-solar metallicities in the solar vicinity

2019 ◽  
Vol 623 ◽  
pp. A99 ◽  
Author(s):  
G. Guiglion ◽  
C. Chiappini ◽  
D. Romano ◽  
F. Matteucci ◽  
F. Anders ◽  
...  
Keyword(s):  
Travel Time ◽  
Chemical Evolution ◽  
Stellar Model ◽  
Solar Neighborhood ◽  
Lithium Content ◽  
Lithium Abundance ◽  
Radial Migration ◽  
Disk Formation ◽  
Solar Metallicity ◽  
Lithium Enrichment

We propose here that the lithium decrease at super-solar metallicities observed in high-resolution spectroscopic surveys can be explained by the interplay of mixed populations that originate in the inner regions of the Milky Way disk. The lower lithium content of these stars is a consequence of inside-out disk formation plus radial migration. In this framework, local stars with super-solar metallicities would have migrated to the solar vicinity and depleted their original lithium during their travel time. To obtain this result, we took advantage of the AMBRE catalog of lithium abundances combined with chemical evolution models that take into account the contribution to the lithium enrichment by different nucleosynthetic sources. A large proportion of migrated stars can explain the observed lower lithium abundance at super-solar metallicities. We stress that no stellar model is currently able to predict Li-depletion for these super-solar metallicity stars, and solar Li-depletion has to be assumed. In addition, no solid quantitative estimate of the proportion of migrated stars in the solar neighborhood and their travel time is currently available. Our results illustrate how important it is to properly include radial migration when chemical evolution models are compared to observations, and that in this case, the lithium decrease at larger metallicities does not necessarily imply that stellar yields have to be modified, contrary to previous claims in the literature.

Chemical evolution of interstellar dust, comets and the origins of life

1989 ◽  
Vol 14 (2) ◽  
pp. 103-131 ◽  
Author(s):  
J. Mayo Greenberg ◽  
Nansheng Zhao ◽  
Joniek Hage
Keyword(s):  
Chemical Evolution ◽  
Interstellar Dust ◽  
Origins Of Life
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