Related papers: v_\perp CMD
We present a novel approach to draw the synthetic color-magnitude diagram of galaxies, which can provide - in principle - a deeper insight in the interpretation and understanding of current observations. In particular, we `light up' the…
It has recently been suggested that the stars in a vertical extension of the red clump feature seen in LMC color-magnitude diagrams could belong to a tidal stream of material located in front of that galaxy. If this claim is correct, this…
An analysis of the observed characteristics of the Galactic Cepheid variables is carried out in the framework of their period-luminosity relation being used as a standard candle for distance measurement. The variation of the observed number…
The color-magnitude diagram (CMD) of globular cluster NGC1651 has special structures including a broad main sequence, an extended main sequence turn-off and an extended red giant clump. The reason for such special CMDs remains unclear. In…
By relying on recently improved Hipparcos parallaxes for the Hyades, Pleiades and Ursa Major clusters we find that stellar models with updated physical inputs nicely reproduce the location in the color magnitude diagram of main sequence…
I study the importance of the accurate calibration of photometric systems in order to produce meaningful comparisons between the observed colors + magnitudes and model SEDs. Possible sources of errors are discussed and two examples are…
For Hipparcos M, S, and C spectral type stars, we provide calibrated instantaneous (epoch) Cousins $V-I$ color indices using newly derived $HpV_{T2}$ photometry. Three new sets of ground-based Cousins $VI$ data have been obtained for more…
Two motions in the galactic plane have been detected and characterized, based on the determination of a common systematic component in Hipparcos catalogue proper motions. The procedure is based only on positions, proper motions and…
We present an empirical method to derive photometric metallicity, reddening and distance to old stellar populations by using a few major features of the Red Giant Branch (RGB) in near IR color magnitude diagrams. We combine the observed RGB…
In this paper HIPPARCOS astrometric and kinematic data are used to calibrate both infrared luminosities and kinematical parameters of Long Period Variable stars (LPVs). Individual absolute K and IRAS 12 and 25 luminosities of 800 LPVs are…
Since the Hipparcos mission and recent large scale surveys in the optical and the near-infrared, new constraints have been obtained on the structure and evolution history of the Milky Way. The population synthesis approach is a useful tool…
We investigate the potential of multi-colour photometry for partial mode identification in both long- and short-period variable subdwarf B stars. The technique presented is based on the fact that the frequency dependence of an oscillation's…
The Hipparcos mission has made it possible to constrain the positions of nearby field stars in the colour-magnitude diagram with very high accuracy. These positions can be compared with the predictions of stellar evolutionary calculations…
We investigate the color-magnitude diagram (CMD) of cluster galaxies in the hierarchical $\Lambda$-CDM cosmological scenario using both single stellar populations and simple galaxy models. First, we analyze the effect of bursts and mergers…
The oscillation spectra of solar-type stars may in the not-too- distant future be used to constrain certain properties of the stars. The CD diagram of large versus small frequency separations is one of the powerful tools available to infer…
An overview of pulsating variable stars across the observational Hertzprung-Russel (HR) diagram is presented, together with a summary of their global properties. The HR diagram is presented with a third colour-coded dimension, visualizing…
A tomographic method, aiming at probing velocity fields at depth in stellar atmospheres, is applied to the red supergiant star {\mu} Cep and to snapshots of 3D radiative-hydrodynamics simulation in order to constrain atmospheric motions and…
I will show that photometry -- if extending over a reasonable choice of passbands -- can give fairly precise information about young star clusters and their evolutionary state. Optical colors alone are known to leave severe ambiguities due…
During the last decade, the understanding of fine features of the structure and evolution of stars has become possible as a result of enormous progress made in the acquisition of high-quality observational and experimental data and of new…
The study of non-thermal processes such as synchrotron emission, inverse Compton scattering, bremsstrahlung and pion production is crucial to understand the properties of the Galactic cosmic-ray population, to shed light on their origin and…