Related papers: Constraining Extra Mixing during the Main Sequence…
Mapping lithium evolution for evolved stars will provide restrictions and constraints on the fundamental stellar interior physical processes, which further shed light on our understanding of the theory of stellar structure and evolution.…
We find that hot jupiter host stars within the T$_\mathrm{eff}$ range 5900-6300K show lower Li abundances, by 0.14 dex, than stars without detected planets. This offset has a significance at the level 7$\sigma$, pointing to a stronger…
Lithium abundance A(Li) and surface rotation are good diagnostic tools to probe the internal mixing and angular momentum transfer in stars. We explore the relation between surface rotation, A(Li) and age in a sample of seismic…
Despite the fact that the initial helium abundance is an essential ingredient in modelling solar-type stars, its abundance in these stars remains a poorly constrained observational property. This is because the effective temperature in…
The primordial abundance of deuterium (D/H) yields a measure of the density of baryons in the universe and is an important complement to determinations from cosmic microwave background (CMB) experiments. Indeed, the current small sample of…
A sample of metal-poor subgiants has been observed with the UVES spectrograph at the Very Large Telescope and abundances of Li and Be have been determined. Typical signal-to-noise per spectral bin values for the co-added spectra are of the…
The mechanisms responsible for chemical depletion across diverse astrophysical environments are not yet fully understood. In this paper, we investigate chemical depletion in post-AGB/post-RGB binary stars hosting second-generation…
We present an extensive study of lithium abundances in dwarf components of chromospherically active binary stars (CABS). Since most of these binaries have known radii, masses and ages, this kind of data is especially useful for comparisons…
Lithium is extensively known to be a good tracer of non-standard mixing processes occurring in stellar interiors. We present the results of a new large Lithium survey in red giant stars and combine it with surveys from the literature to…
As potential progenitors of several exotic phenomena including gravitational wave sources, magnetic stars, and Be stars, close massive binary systems probe a crucial area of the parameter space in massive star evolution. Despite the…
The detection of mixed oscillation modes offers a unique insight into the internal structure of core helium burning (CHeB) stars. The stellar structure during CHeB is very uncertain because the growth of the convective core, and/or the…
The nucleosynthesis of Be and B by spallation processes provides unique insight into the origin of cosmic rays. Namely, different spallation schemes predict sharply different trends for the growth of LiBeB abundances with respect to oxygen.…
We show that non-magnetic models for the evolution of pre-main-sequence (PMS) stars *cannot* simultaneously describe the colour-magnitude diagram (CMD) and the pattern of lithium depletion seen in the cluster of young, low-mass stars…
The current status of observational studies of lithium depletion in open clusters is reviewed, concentrating mainly on G and K type stars. I attempt to answer the following questions: Can the lithium depletion patterns seen in open clusters…
We have observed high-dispersion echelle spectra of main-sequence stars in five nearby young associations -- Argus, Carina-Near, Hercules-Lyra, Orion and Subgroup B4 -- and derived abundances for elements ranging from Na to Eu. These are…
Boron abundances in A- and B-type stars may be a successful way to track evolutionary effects in these hot stars. The light elements -- Li, Be, and B -- are tracers of exposure to temperatures more moderate than those in which the H-burning…
The element beryllium is detected for the first time in white dwarf stars. This discovery in the spectra of two helium-atmosphere white dwarfs was made possible only because of the remarkable overabundance of Be relative to all other…
The rotation rate, level of magnetic activity and surface lithium abundance are age-dependent quantities in stars of about a solar mass and below. The physical reasons for the evolution of these phenomena are qualitatively understood, but…
We have computed new solar models using the same stellar evolution code as described in Charbonnel, Vauclair and Zahn (1992). This code, originating from Geneva, now includes the computation of element segregation for helium and 12 heavier…
The possibility that the so-called "lithium problem", i.e. the disagreement between the theoretical abundance predicted for primordial $^7$Li assuming standard nucleosynthesis and the value inferred from astrophysical measurements, can be…