Related papers: The Interstellar $^7$Li/$^6$Li Ratio
Laser inter-satellite links (LISLs) are envisioned between satellites in upcoming satellite constellations, such as Phase I of SpaceX's Starlink. Within a constellation, satellites can establish LISLs with other satellites in the same…
There has been recent progress in the study of the angular momentum evolution of low mass stars (Krishnamurthi et al 1997a). Theoretical models can now be constructed which reproduce the angular momentum evolution of low mass open cluster…
Optical interferometry provides us with a unique opportunity to improve our understanding of stellar structure and evolution. Through direct observation of rotationally distorted photospheres at sub-milliarcsecond scales, we are now able to…
Lithium is one of the few elements produced during the Big Bang Nucleosynthesis in the early universe. Moreover, its fragility makes it useful as a proxy for stellar environmental conditions. As such, the lithium abundance in old systems is…
We derive lithium abundances in 53 T Tauri stars (TTS), concentrating on weak-line TTS. Our study gives the following results: 1)At luminosities $\ge 0.9 L\sun$ the Li abundances are remarkably uniform, with a mean value, log~N(Li)=3.1,…
We review the main sources of LiBeB production and show that a primary mechanism is at work in the early Galaxy involving both ejection and acceleration of He, C and O at moderate energy, which by nuclear interaction with H and He produce…
The present work aims to examine in detail the depletion of lithium in solar twins to better constrain stellar evolution models and investigate its possible connection with exoplanets. We employ spectral synthesis in the region of the…
We examine the evolution of Li in the Galactic disk,basing our model on the compilation of Li v.Fe observations in stars of iron abundance ranging between halo values,which give a baseline for the disk Li abundance,and 0.2 dex above…
A short overview is presented of the role that Low and Intermediate mass stars play in Galactic Chemical Evolution; their action affects key elements and isotopes, like deuterium, He-3, Li-7, carbon and nitrogen, and s-process nuclei. In…
The isotope ratio, 85Rb/87Rb, places constraints on models of the nucleosynthesis of heavy elements, but there is no precise determination of the ratio for material beyond the Solar System. We report the first measurement of the…
A search for lithium is performed on seven metal poor dwarfs with metallicities ranging from [Fe/H]=-1.5 down to [Fe/H]=-3.0 but showing disk-like kinematics. These stars belong to the metal poor tail of the Galactic thick disk and they may…
The cosmological Li problem is the observed discrepancy between Li abundance, A(Li), measured in Galactic dwarf, old and metal-poor stars (traditionally assumed to be equal to the initial value A(Li)_0), and that predicted by standard Big…
Isotopic ratios provide a powerful tool for understanding the origins of materials, including the volatile and refractory matter within solar system bodies. Recent high sensitivity observations of molecular isotopologues, in particular with…
The origin of the observed variability of the gas-phase D/H ratio in the local interstellar medium is still debated, and in particular the role of deuterium depletion onto dust grains. Here we extend the study of the relationship between…
The observed amount of lithium for low metallicity population II stars (known as the Spite plateau) is a factor of $\sim 3-5$ lower than the predictions of the standard cosmology. Since the observations are limited to the local Universe…
The dispersion in lithium abundance at fixed effective temperature in young cool stars like the Pleiades has proved a difficult challenge for stellar evolution theory. We propose that Li abundances relative to a mean temperature trend,…
The deuterium abundance evaluation in the direction of Capella has for a long time been used as a reference for the local interstellar medium (ISM) within our Galaxy. We show here that broad and weak HI components could be present on the…
Precise studies on the Galactic bulge, halo, thick disk, and globular clusters require stellar models with alpha enhancement and various He contents. For this purpose we complement existing PARSEC (PAdova-TRieste Stellar Evolution Code)…
We perform non-LTE calculations of lithium in late-type stars for a wide range of stellar parameters, including quantum mechanical cross-sections for collisions with neutral hydrogen and the negative hydrogen ion. Non-LTE abundance…
Because the ionization balances for HI, OI, and DI are locked together by charge exchange, D/O is an important tracer for the value of the D/H ratio and for potential spatial variations in the ratio. As the DI and OI column densities are of…