Related papers: Variable stars in Stellar Systems
In this review we focus on non-linear phenomena in pulsating stars the mode selection and amplitude limitation. Of many linearly excited modes only a fraction is detected in pulsating stars. Which of them and why (the problem of mode…
We present B, V and I CCD light curves for 101 variable stars belonging to the globular cluster NGC2419, 60 of which are new discoveries, based on datasets obtained at the TNG, SUBARU and HST telescopes. The sample includes 75 RR Lyrae…
We present the results of a search for variable stars in the faint sparse globular cluster E3. We have found two variable stars: an SX Phe variable (V1) and a W UMa eclipsing binary (V2). We have applied period-luminosity and…
Following the discovery of blue large-amplitude pulsators (BLAPs) by the OGLE survey, additional hot, high-amplitude pulsating stars have been discovered by the Zwicky Transient Facility. It has been proposed that all of these objects are…
Integrated spectrophotometric properties of stellar systems are intrinsically dispersed due to the stochastic nature of the small numbers of bright stars they contain. Among clusters, only the most massive ones can be used individually for…
Internal dynamical evolution can drive stellar systems into states of high central density. For many star clusters and galactic nuclei, the time scale on which this occurs is significantly less than the age of the universe. As a result,…
An increasing number of both photometric and spectroscopic observations over the last years have shown the existence of distinct sub-populations in many Galactic globular clusters and shattered the paradigm of globulars hosting single,…
We present a study of photometric properties of very crowded stellar fields toward the Galactic Bulge. We performed a search for pulsating stars among thousands of variable stars from the OGLE-II survey supplementing the variability study…
The field of the globular cluster NGC 6362 was monitored between 1995 and 2009 in a search for variable stars. BV light curves were obtained for 69 periodic variables including 34 known RR Lyr stars, 10 known objects of other types and 25…
This is the third in a series of papers studying the variable stars in old globular clusters in the Large Magellanic Cloud. The primary goal of this series is to look at how the characteristics and behavior of RR Lyrae stars in…
High sensitivity searches of globular clusters (GC) for radio pulsars by improved pulsar search algorithms and sustained pulsar timing observations have so far yielded some 140 pulsars in more than two dozen GCs. The observed distribution…
The Doppler effect is commonly used to infer the velocity difference between stars based on the relative shifts in the rest-frame wavelengths of their spectral features. In dynamically-cold systems with a low velocity dispersion, such as…
Populations of young star clusters show significant differences even among "normal" disk galaxies. In this contribution I discuss how properties of young cluster systems are related to those of their host galaxies, based on a recent study…
We present new observations of Sextans and Leo I dwarf galaxies, that provide new insight on their stellar populations. The large sample of stars measured in Sextans allowed us to obtain a reliable estimate of the metal content of this…
Context. Globular clusters (GCs) are witnesses of the past accretion events onto the Milky Way (MW). In particular, the GCs of the Sagittarius (Sgr) dwarf galaxy are important probes of an on-going merger. Aims. Our main goal is to search…
An increasing number of photometric observations of multiple stellar populations in Galactic globular clusters is seriously challenging the paradigm of GCs hosting single, simple stellar populations. These multiple populations manifest…
The long-time photometric surveys in a few young open clusters allowed to identify the light variability in stars located on the HR diagram between the well defined $\delta$ Scuti variables and Slowly Pulsating B-type stars. Several objects…
In this contribution, first results of deep VLT photometry (V,I) in the central region of the Hydra I and Centaurus galaxy clusters are presented. In both galaxy clusters, many star clusters have been identified down to the turnover…
The star formation histories of Local Group galaxies are summarized. The three large spirals are discussed individually, whereas the discussion of the Local Group dwarfs concentrates on differences and commonalities. While Local Group…
Blue stragglers are natural phenomena in star clusters. They originate through mass transfer in isolated binaries, as well as through encounters between two or more stars, in a complex interplay between stellar dynamics and stellar…