Related papers: Variable stars in Stellar Systems
Three fields covering the central part of the globular cluster Omega Cen were surveyed in a search for variable stars. We present V-band light curves for 22 periodic variables: 9 SX~Phe stars, 7 contact binaries, 5 detached or semi-detached…
We investigate the variable star content of the isolated, Local Group, dwarf spheroidal galaxy (dSph) Cetus. Multi-epoch, wide-field images collected with the VLT/VIMOS camera allowed us to detect 638 variable stars (630 RR Lyrae stars and…
Globular star clusters that formed at the same cosmic time may have evolved rather differently from a dynamical point of view (because that evolution depends on the internal environment) through a variety of processes that tend…
We present the first dynamical study of Blue Straggler Stars (BSSs) in three Galactic globular clusters, NGC\,3201, NGC\,5139 ($\omega$Cen), and NGC\,6218, based on medium-resolution spectroscopy (R 10000) obtained with IMACS. Our BSS…
We present theoretical predictions concerning horizontal branch stars in globular clusters, including RR Lyrae variables, as derived from synthetic procedures collating evolutionary and pulsational constraints. On this basis, we explore the…
We have undertaken a near-IR spectral survey of stars associated with compact nebulae recently revealed by the Spitzer and WISE imaging surveys. These circumstellar nebulae, produced by massive evolved stars, display a variety of symmetries…
We know from observations that globular clusters are very efficient catalysts in forming unusual short-period binary systems or their offspring, such as low-mass X-ray binaries (LMXBs; neutron stars accreting matter from low-mass stellar…
There are a few different mechanisms that can cause white dwarf stars to vary in brightness, providing opportunities to probe the physics, structures, and formation of these compact stellar remnants. The observational characteristics of the…
In this paper we report on the most significant results from a statistical analysis of the main properties of globular cluster blue straggler stars (BSS) extracted from the HST snapshot database of photometrically homogeneous CMDs (Piotto…
Aims. We analyze the population of periodic variable stars in the open cluster NGC 3766 based on a 7-year multi-band monitoring campaign conducted on the 1.2 m Swiss Euler telescope at La Silla, Chili. Methods. The data reduction, light…
Galactic globular clusters are old, dense star systems typically containing 10\super{4}--10\super{7} stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars,…
The last fifteen years have seen the discovery of new types of low-mass stellar systems that bridge the gap between the once well-separated regimes of galaxies and of star clusters. Whether such objects are considered galaxies depends also…
Blue stragglers in globular clusters are abnormally massive stars that should have evolved off the stellar main sequence long ago. There are two known processes that can create these objects: direct stellar collisions and binary evolution.…
This is the second in a series of papers studying the variable stars in Large Magellanic Cloud globular clusters. The primary goal of this series is to study how RR Lyrae stars in Oosterhoff-intermediate systems compare to their…
We report on the discovery and analysis of 14 short-period variable stars in the field of the southern globular cluster NGC 3201, located within roughly two magnitudes on either side of the main-sequence turnoff. 11 of these variable stars…
The characteristics and properties of the stellar populations and evolutionary histories of Local Group galaxies are summarized and compared to predictions of cosmological models. No clear signature of the re-ionization epoch is observed;…
I will discuss the presence of massive star clusters in starburst galaxies with an emphasis on low mass galaxies outside the local group. I will show that such galaxies, with respect to their mass and luminosity, may be very rich in young…
I point out that the Oosterhoff dichotomy for globular cluster and field RR Lyrae (RRL) stars may place the strongest constraints so far on the number of dwarf spheroidal-like protogalactic fragments that may have contributed to the…
This review summarizes the properties of the stellar population in bulges as observed in nearby or distant spiral galaxies. It gives a particular emphasis to the comparison with elliptical galaxies, when possible. The criteria of sample…
I review recent and less recent work on globular cluster systems in early-type galaxies. Explaining their properties and possible assembly scenarios, touches on a variety of astrophysical topics from cluster formation itself to galaxy…