Related papers: Luminosity-Colours relations for thin disc main-se…
Understanding the age and metallicity dependence of the absolute magnitude and colour of red clump (RC) stars is crucial for validating the accuracy of stellar evolution models and enhancing their reliability as a standard candle. However,…
We present improved visual and near-infrared empirical mass-luminosity relations for very low mass stars (M$<$0.6~\Msol). These relations make use of all stellar masses in this range known with better than 10% accuracy, most of which are…
The development of sensitive large format imaging arrays for the infrared promises to provide revolutionary capabilities for space astronomy. For example, the Infrared Array Camera (IRAC) on SIRTF will use four 256 x 256 arrays to provide…
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…
We estimated the Galactic model parameters by means of a new approach based on the comparison of the observed space density functions per absolute magnitude interval with a unique density law for each population individually, and via the…
Wilson and Bappu (1957) have shown the existence of a remarkable correlation between the width of the emission in the core of the K line of Ca II and the absolute visual magnitude of late--type stars. Here we present a new calibration of…
Our knowledge about unresolved stellar systems comes from comparing integrated-light properties to SSP models. Therefore it is crucial to calibrate the latter as well as possible by integrated-light colors of clusters that have reliable…
There is a clear scarcity of structural parameters for stellar thick discs, especially for spiral galaxies located in high-density regions, such as galaxy clusters and compact groups. We have modelled the thin and thick discs of 4 edge-on…
We compare the absolute visual magnitude of the majority of bright O stars in the sky as predicted from their spectral type with the absolute magnitude calculated from their apparent magnitude and the Hipparcos parallax. We find that many…
We present new grids of colors and bolometric corrections for F-K stars having 4000 K < Teff < 6500 K, 0.0 < log g < 4.5 and -3.0 < [Fe/H] < 0.0. A companion paper extends these calculations into the M giant regime. Colors are tabulated for…
We characterize the absolute magnitudes and colors of RR Lyrae stars in the globular cluster M5 in the ugriz filter system of the Dark Energy Camera (DECam). We provide empirical Period-Luminosity (P-L) relationships in all 5 bands based on…
The mass-luminosity relation for late-type stars has long been a critical tool for estimating stellar masses. However, there is growing need for both a higher-precision relation and a better understanding of systematic effects (e.g.,…
We analyse the phase-space structure of simulated thick discs that are the result of a significant merger between a disc galaxy and a satellite. Our main goal is to establish what would be the characteristic imprints of a merger origin for…
Based on a large sample of disk and halo giant stars, for which accurate effective temperatures derived through the InfraRed Flux Method (IRFM) exist, a calibration of the temperature scale in the Vilnius, Geneva, RI(C) and DDO photometric…
We present a theoretical calibration of a new metallicity diagnostic based on the Stroemgren index m1 and on visual -- near-infrared (NIR) colors to estimate the global metal abundance of cluster and field dwarf stars. To perform the…
We present calibrations for star formation rate indicators in the ultraviolet, mid-infrared and radio continuum bands, including one of the first direct calibrations of 150 MHz as a star formation rate indicator. Our calibrations utilize 66…
A new calibration of the Mv-W(OI 7774) relationship has been calculated using better estimates of reddenings and distances to a sample of 27 calibrator stars of A-G spectral types, based on accurate parallaxes and proper motions from the…
We study the distribution of nearby thick disc and halo stars in subspaces defined by their characteristic orbital parameters. Our aim is to establish the origin of the structure reported in particular, in the $R_{\rm max}-z_{\rm max}$…
Evolutionary and atmospheric models have become available for young ultralow-mass objects. These models are being used to determine fundamental parameters from observational properties. TiO bands are used to determine effective temperatures…
The next generation near- and mid-infrared Galactic surveys will yield a large number of new highly obscured star clusters. Detailed characterization of these new objects with spectroscopy is time-consuming. Diagnostic tools that will be…