Related papers: The cosmological lithium problem
We model early star forming regions and their chemical enrichment by Population III (Pop III) supernovae with nucleosynthetic yields featuring high [C/Fe] ratios and pair-instability supernova (PISN) signatures. We aim to test how well…
To understand the chemical evolution of the Galaxy, we need to understand the contribution of PNe in the 3He abundance. 3He abundances have been detected only in a couple of PNe, their abundances are consistent with the standard models, in…
After the Big Bang nucleosynthesis, the first heavy element enrichment in the Universe was made by a supernova (SN) explosion of a population (Pop) III star (Pop III SN). The abundance ratios of elements produced from Pop III SNe are…
Using observations of rapidly rotating roAp star HD 12098, obtained with 6m telescope of SAO RAS in 2005-2008 in nine rotational phases (0.001-0.817), and code V. Tsymbal ROTATE we identified 3 lithium spots on the surface of star, one of…
The primordial abundances of Deuterium, he4, and li7 are crucial to determination of the baryon density of the Universe in the framework of standard Big Bang nucleosynthesis (BBN). li6 which is only produced in tiny quantities and it is…
Context. Recently, for the first time the abundance of P has been measured in disk stars. This provides the opportunity of comparing the observed abundances with predictions from theoretical models. Aims. We aim at predicting the chemical…
Context. Galactic red novae are thought to be produced in stellar mergers between non-compact stars, such as main-sequence stars and cool giants. They are hoped to help in explaining physical processes involved in common envelope evolution…
Recent spectroscopic observations of metal poor stars have indicated that both $^7$Li and $^6$Li have abundance plateaus with respect to the metallicity. Abundances of $^7$Li are about a factor three lower than the primordial abundance…
The source of the Galactic Lithium (Li) has long been a puzzle. With the discovery of Li in novae, extensive research has been conducted. However, there still exists a significant disparity between the observed abundance of lithium in novae…
A highly homogeneous study of 23 halo field dwarf stars has achieved a Li abundance accuracy of 0.033 dex per star. The work shows that the intrinsic spread of the Li abundances of these stars at a given metallicity is <0.02 dex, and…
With the first metal enrichment by Population (Pop) III supernovae (SNe), the formation of the first metal-enriched, Pop II stars becomes possible. In turn, Pop III star formation and early metal enrichment are slowed by the high energy…
We review three Li problems. First, the Li problem in the Sun, for which some previous studies have argued that it may be Li-poor compared to other Suns. Second, we discuss the Li problem in planet hosting stars, which are claimed to be…
We review recent 3D cosmological hydrodynamic simulations of primordial star formation from cosmological initial conditions (Pop III.1) and from initial conditions that have been altered by radiative feedback from stellar sources (Pop…
The AEOS project introduces a series of high-resolution cosmological simulations that model star-by-star chemical enrichment and galaxy formation in the early Universe, achieving 1 pc resolution. These simulations capture the complexities…
We report results from lithium abundance determinations using high resolution spectral analysis of the 107 metal-rich stars from the Calan-Hertfordshire Extrasolar Planet Search programme. We set out to understand the lithium distribution…
Recent WMAP observations indicate that the primordial abundance of lithium should have been 2-4 times higher than the value measured in low-metallicity stars. We show that this discrepancy can be explained by the process of ambipolar…
Aims: The purpose of our study is to determine the chemical composition of a sample of 16 candidate Extremely Metal-Poor (EMP) dwarf stars, extracted from the Sloan Digital Sky Survey (SDSS). There are two main purposes: in the first place…
We have determined Li abundances for eleven metal-poor turn-off stars, among which eight have [Fe/H]<-3, based on LTE analyses of high-resolution spectra obtained with the HDS on the Subaru telescope. The Li abundances for four of these…
The light element lithium is formed by nucleosynthesis during the Big Bang. Its abundance can help to define the parameters of the early universe. To find this primordial value, it is necessary to determine Li abundances in the oldest stars…
Thanks to the high multiplex and efficiency of Giraffe at the VLT we have been able for the first time to observe the Li I doublet in the Main Sequence (MS) stars of a Globular Cluster. At the same time we observed Li in a sample of…