Related papers: Light elements in stars with exoplanets
The bulk-metallicity determination of giant exoplanets is essential to constrain their formation and evolution pathways and to compare them to the solar system. Previous studies inferred an inverse relation between the mass and bulk…
The element settling due to the combined effects of gravity, thermal gradient, radiative acceleration and concentration gradient may lead to important abundance variations inside the stars, which cannot be neglected in the computations of…
When searching for exoplanets and ultimately considering their habitability, it is necessary to consider the planet's composition, geophysical processes, and geochemical cycles in order to constrain the bioessential elements available to…
The correlation between stellar metallicity and the presence of giant planets is well established. It has been tentatively explained by the possible increase of planet formation probability in stellar disks with enhanced amount of metals.…
The orders of magnitude variation in lithium abundances of evolved stars have long been a puzzle. Diluted signals, ambiguous evolutionary states and unknown masses have made it challenging to both map the expected lithium signals and…
We describe observations and abundance analysis of a high-resolution, high-S/N survey of 168 stars, most of which are metal-poor dwarfs. We follow a self-consistent LTE analysis technique to determine the stellar parameters and abundances,…
The discovery of a truly habitable exoplanet would be one of the most important events in the history of science. However, the nature and distribution of habitable environments on exoplanets is currently unconstrained. The exoplanet…
Context. The discovery of about 700 extrasolar planets, so far, has lead to the first statistics concerning extrasolar planets. The presence of giant planets seems to depend on stellar metallicity and mass. For example, they are more…
We present a series of systematic abundance measurements for 25 hot DA white dwarfs in the temperature range ~20000-110000K, based on far-UV spectroscopy with STIS/GHRS on HST, IUE and FUSE. Using our latest heavy element blanketed non-LTE…
The chemical evolution of the Galactic bulge is treated here in the context of an inside-out model for the Galaxy formation. We assume that this central region evolved even faster than the Galactic halo and test the effect of changing the…
The large majority of stars in the Milky Way are late-type dwarfs, and the frequency of low-mass exoplanets in orbits around these late-type dwarfs appears to be high. In order to characterize the radiation environments and habitable zones…
Aims. Exoplanet-host stars (EHS) are known to present superficial chemical abundances different from those of stars without any detected planet (NEHS). EHS are, on the average, overmetallic compared to the Sun. The observations also show…
Stars and their associated planets originate from the same cloud of gas and dust, making a star's elemental composition a valuable indicator for indirectly studying planetary compositions. While the connection between a star's iron (Fe)…
We review the field of abundance determinations of elements in cool stars, with special interest paid to determinations based on analyses of high-resolution, 1-5 micron spectra. We discuss the current status, problems, and challenges of…
New elemental abundances for the neutron-capture elements Sr, Nb, Mo, Ru, La, Sm, and Eu are presented for a large sample of 180 barium (Ba) giant stars, a class of chemically peculiar objects that exhibit in their spectra enhancements of…
The properties of 322 intermediate-mass late-G giants (comprising 10 planet-host stars) selected as the targets of Okayama Planet Search Program, many of which are red-clump giants, were comprehensively investigated by establishing their…
Context: Chemical abundances of light elements as beryllium in planet-host stars allow us to study the planet formation scenarios and/or investigate possible surface pollution processes. Aims: We present here an extension of previous…
This paper gives an overview of the properties of all possible equilibrium sequences of compact strange-matter stars with nuclear crusts, which range from strange stars to strange dwarfs. In contrast to their non-strange counterparts,…
The observed oxygen abundances in a number of irregular galaxies have been compared with predictions of the closed-box model of chemical and photometric evolution of galaxies. Oxygen is found to be deficient with respect to the predicted…
Deep elemental composition is a challenging measurement to achieve in the giant planets of the solar system. Yet, knowledge of the deep composition offers important insights in the internal structure of these planets, their evolutionary…