Related papers: v_\perp CMD
Massive star winds are important contributors to the energy, momentum and chemical enrichment of the interstellar medium. Strong, organized and predominantly dipolar magnetic fields have been firmly detected in a small subset of massive…
In this letter, we study the cosmological dynamics of steeper potential than exponential. Our analysis shows that a simple extension of an exponential potential allows to capture late-time cosmic acceleration and retain the tracker…
We present preliminary results of the generalized Principal Component Analysis (PCA) of light curves of 82 magnetic chemically peculiar (further mCP) stars applied to 54 thousand individual photometric observations in the uvby and Hp…
Stars are not smooth. Their photosphere is covered by a granulation pattern associated with the heat transport by convection. The convection-related surface structures have different size, depth, and temporal variations with respect to the…
The Hipparcos data allow a major step forward in the research of `moving groups' in the Solar neighbourhood, as the common motion of group members causes converging proper motions. Previous knowledge on these coherent structures in velocity…
Our fundamental lack of understanding of the acceleration of the Universe suggests that we consider a kinematic description. The simplest formalism involves the third derivative of the scale factor through a jerk parameter. A new approach…
The Kepler spacecraft is providing photometric time series with micro-magnitude precision for thousands of variable stars. The continuous time-series of unprecedented time span open up opportunities to study the pulsational variability in…
Comparison of stellar catalogues with position and proper motion components using a decomposition on a set of orthogonal vector spherical harmonics. We show the theoretical and practical advantages of this technique as a result of…
Kepler seeks to detect sequences of transits of Earth-size exoplanets orbiting Solar-like stars. Such transit signals are on the order of 100 ppm. The high photometric precision demanded by Kepler requires detailed knowledge of how the…
We investigate the origin of the color-magnitude relation (CMR) observed in cluster galaxies by using a combination of a cosmological N-body simulation of a cluster of galaxies and a semi-analytic model of galaxy formation. The departure of…
We perform a series of numerical experiments to study how the nonlinear metallicity--color relations predicted by different stellar population models affect the color distributions observed in extragalactic globular cluster systems. % We…
A most desirable feature of a standard candle to estimate astronomical distances is robustness against changes in metallicity and age. It is argued that the radii of main sequence stars with spectral types from solar to A0 show predictable…
We have obtained broad-band near-infrared photometry for seven Galactic star clusters (M92, M15, M13, M5, NGC1851, M71 and NGC6791) using the WIRCam wide-field imager on the Canada-France-Hawaii Telescope, supplemented by images of NGC1851…
We present an analysis of the space motions of 742 subdwarf stars based on the sample of Carney et al. (1994, CLLA). Hipparcos parallaxes, TYC2+HIP proper motions and Tycho2 proper motions were combined with radial velocities and…
We present a study of pixel Colour Magnitude Diagrams (pCMDs) for a sample of 69 nearby galaxies chosen to span a wide range of Hubble types. Our goal is to determine how useful a pixel approach is for studying galaxies according to their…
We present observations collected in the CFHTLS-VIPERS region in the ultraviolet (UV) with the GALEX satellite (far and near UV channels) and the near infrared with the CFHT/WIRCam camera ($K_s$-band) over an area of 22 and 27 deg$^2$,…
Theoretical integrated broad-band colors ranging from far-UV to near-IR have been computed for old stellar systems from our evolutionary population synthesis code. These models take into account, for the first time, the detailed systematic…
We present new periodograms that are effective in distinguishing Doppler shift from spectral shape variability in astronomical spectra. These periodograms, building upon the concept of partial distance correlation, separate the periodic…
The emergence of optical interferometers with three and more telescopes allows image reconstruction of astronomical objects at the milliarcsecond scale. However, some objects contain components with very different spectral energy…
The absolute K magnitudes and kinematic parameters of about 350 oxygen-rich Long-Period Variable stars are calibrated, by means of an up-to-date maximum-likelihood method, using Hipparcos parallaxes and proper motions together with radial…