Related papers: More on pulsating B-type stars in the Magellanic C…
The Hubble Space Telescope has provided the first clear evidence for weaker winds of metal-poor massive stars in the Small Magellanic Cloud, confirming theoretical predictions of the metallicity dependence of mass-loss rates and wind…
This document presents the results from our spectroscopic survey of Halpha emitters in galactic and SMC open clusters with the ESO Wide Field Imager in its slitless spectroscopic mode. First of all, for the galactic open cluster NGC6611, in…
A number of microlensing dark-matter surveys have produced tens of millions of light curves of individual background stars. These data provide an unprecedented opportunity for systematic studies of whole classes of variable stars and their…
I present measurements of the projected rotational velocities of a sample of 100 early B-type main-sequence stars in the Large Magellanic Cloud. This is the first extragalactic study of the distribution of stellar rotational velocities. The…
Despite a resurgence of effort over the last decade in the area of massive stars there is still ambiguity over their evolutionary path, contamination of their surface abundances and the behaviour of their stellar winds. Here 10 SMC B-type…
Knowledge of the geometry of pulsational modes is a prerequisite for seismic modelling of stars. In the case of slowly pulsating B-type (SPB) pulsators, the simple zero-rotation approach so far used for mode identification is usually not…
The color-magnitude diagrams (CMDs) of young star clusters show that, particularly at ultraviolet wavelengths, their upper main sequences (MSs) bifurcate into a sequence comprising the bulk population and a blue periphery. The spatial…
Aims. In order to better model massive B-type stars, we need to understand the physical processes taking place in slowly pulsating B (SPB) stars, chemically peculiar Bp stars, and non-pulsating normal B stars co-existing in the same part of…
Recent observational and theoretical results emphasize the potential significance of magnetic fields for structure, evolution, and environment of massive stars. Depending on their spectral and photometric behavior, the upper main-sequence…
We analysed ASAS-3 photometry of bright early-type stars with the goal of finding new Beta Cephei stars. We were particularly interested in stars that would be good for seismic analysis, i.e., stars that (i) have a large number of excited…
This is a catalogue of approximately 70 X-ray emitting binary systems in the Small Magellanic Cloud (SMC) that contain a Be star as the mass donor in the system and a clear X-ray pulse signature from a neutron star. The systems are…
The spectral distributions of Be/X-ray binaries in the Large Magellanic Cloud and Galaxy have been shown to differ significantly from the distribution of isolated Be stars in the Galaxy. Population synthesis models can explain this…
Pulsating variable stars can be powerful tools to study the structure, formation and evolution of galaxies. I discuss the role that the Magellanic Clouds' pulsating variables play in our understanding of the whole Magellanic System, in…
The number ratios Be/(B+Be) of Be to B-type stars in young, well studied clusters of the Galaxy, the LMC and SMC are examined. In order to disentangle age and metallicity effects we choose clusters in the same age interval and for which…
The excitation of pulsation modes in beta Cephei and Slowly Pulsating B stars is known to be very sensitive to opacity changes in the stellar interior where T~2 10^5 K. In this region differences in opacity up to ~50% can be induced by the…
We search for new variable B-type pulsators in the CoRoT data assembled primarily for planet detection, as part of CoRoT's Additional Programme. We aim to explore the properties of newly discovered B-type pulsators from the uninterrupted…
The slowly pulsating B (SPB) stars are a class of variable star with masses between about 3 and 8 M$_{\odot}$. Their gravity-mode pulsation frequencies are sensitive to the near-core structure, which makes them useful probes of rotation and…
The Small Magellanic Cloud (SMC) hosts a large number of high-mass X-ray binaries, and in particular of Be/X-ray Binaries (BeXRBs; neutron stars orbiting OBe-type stars), offering a unique laboratory to address the effect of metalicity. One…
At low metallicity the B-type stars rotate faster than at higher metallicity, typically in the SMC. As a consequence, it was expected a larger number of fast rotators in the SMC than in the Galaxy, in particular more Be/Oe stars. With the…
Complete samples of 2MASS stars in 3 fields of differing metallicities (and possibly differing age distributions) have been extracted and cross-correlated with MACHO and ISO data to determine their variability and mass-loss properties. In…