Related papers: Clump stars in the Solar Neighbourhood
We present a revised metallicity distribution of dwarfs in the solar neighbourhood. This distribution is centred on solar metallicity. We show that previous metallicity distributions, selected on the basis of spectral type, are biased…
Several recent studies of Solar twins in the Solar neighbourhood have shown a tight correlation between various elemental abundances and age, in particular [Y/Mg]. If this relation is real and valid for other types of stars as well as…
We derive stellar ages, from evolutionary tracks, and metallicities, from Stromgren photometry, for a sample of 5828 dwarf and sub-dwarf stars from the Hipparcos Catalogue. This stellar disk sample is used to investigate the age-metallicity…
The age-metallicity relation for F and G dwarf stars in the solar neighborhood, based on the stellar metallicity data of Edvardsson et al. (1993), shows an apparent scatter that is larger than expected considering the uncertainties in…
New ages are computed for stars in the Solar Neighbourhood from the Edvardsson et al. (1993) data set. Distances derived from the Hipparcos parallaxes were adopted to obtain reliable ages (uncertainty less than 12%) for a subset of stars.…
High-quality Hipparcos data for a complete sample of nearly 12000 main-sequence and subgiant stars, together with Padua isochrones, are used to constrain the star-formation history of the solar neigbourhood and the processes that…
In the age of high-resolution spectroscopic stellar surveys of the Milky Way, the number of stars with detailed abundances of multiple elements is rapidly increasing. These elemental abundances are directly influenced by the evolutionary…
A comparison is made between the age-metallicity relation obtained from four different types of studies: F and G stars in the Solar Neighbourhood, analysis of open clusters, galactic structure studies with the stellar population synthesis…
We address the question of the occurrence of star formation bursts in the solar neighbourhood by using the metallicity distribution of the G dwarfs. We present a method to recover the star formation history using simultaneously the…
New ages are computed for the stars from the Edvardsson et al. (1993) data set. The revised values are systematically larger toward older ages (t>4 Gyr), while they are slightly lower for t<4 Gyr. A similar, but considerably smaller trend…
We discuss the age of the stellar disks in the solar neighbourhood. After reviewing the various methods for age dating we discuss current estimates of the age of both the thin and the thick disk. We present preliminary results for…
The chemical composition of Earth's atmosphere has undergone substantial evolution over the course of its history. It is possible, even likely, that terrestrial planets in other planetary systems have undergone similar changes;…
The age-metallicity relation of the solar neighbourhood is studied using a sample of 552 late-type dwarfs. This sample was built from the intersection of photometric catalogues with chromospheric activity surveys of the Mount Wilson group.…
We derive a new metallicity distribution of G dwarfs in the solar neighbourhood, using uvby photometry and up-to-date parallaxes. Our distribution comprises 287 G dwarfs within 25 pc from the Sun, and differs considerably from the classic…
We discuss the present state of knowledge and thought concerning the spread in age found among Galactic globular clusters, with some discussion of the implications for what happened during the earliest stages of the formation of the Milky…
The large sample of main sequence stars with Hipparcos parallaxes and estimates of the radial velocity has been used to study the relations among kinematics, age and heavy element content for the solar neighbourhood. The samples with V> -30…
The main atmospheric parameters and abundances of the iron group elements (vanadium, chromium, iron, cobalt and nickel) are determined for 62 red giant "clump" stars revealed in the Galactic field by the Hipparcos orbiting observatory. The…
Sun-like dwarf stars in the solar neighborhood reflect ages, an ``average'' chemical evolution, and departures from that average. We show the chemical, and kinematic properties of four groups of Sunlike dwarfs form a continuum related to…
We derive age-metallicity relations (AMRs) and orbital parameters for the 1658 solar neighbourhood stars to which accurate distances are measured by the HIPPARCOS satellite. The sample stars comprise 1382 thin disc stars, 229 thick disc…
Observations of Young Star Cluster ({\bf YSC}) systems in interacting galaxies are reviewed with particular emphasis on their Luminosity Functions ({\bf LF}) and colour distributions. A few spectroscopic abundance measurements are…