Related papers: Dynamical properties and search of variable stars:…

The NASA Kepler spacecraft data revealed a large number of multimode nonradially pulsating gamma Dor and delta Sct variable star candidates. The high precision long time-series photometry makes it possible to study amplitude variations of…

M71 is a nearby, metal-rich globular cluster at low Galactic latitude, where field contamination and spatially variable extinction complicate colour-magnitude diagrams (CMDs) and the identification of cluster member variable stars. Our aims…

Distant regions close to the plane of our Galaxy are largely unexplored by optical surveys as they are hidden by dust. We have used near-infrared data (that minimizes dust obscuration) from the ESO Public survey VISTA Variables of the Via…

The stellar mass-luminosity relation is poorly constrained by observations for high mass stars. We describe our program to find eclipsing massive binaries in the Magellanic Clouds using photometry of regions rich in massive stars, and our…

The magnetic chemically peculiar (CP2) stars of the upper main sequence are well-suited for investigating the impact of magnetic fields on the surface layers of stars, which leads to abundance inhomogeneities (spots) resulting in…

The spatial morphological study of studied clusters is carried out through the identified probable members within them. The field stars decontamination is performed by the statistical cleaning approach (depends on the magnitude and colour…

(abridged) Variability is a key property of stars on the asymptotic giant branch (AGB). Their pulsation period is related to the luminosity and mass-loss rate (MLR) of the star. Long-period variables (LPVs) and Mira variables are the most…

We present the results of a long-term variability survey of the old open cluster NGC 6791. The BVI observations, collected over a time span of 6 years, were analyzed using the ISIS image subtraction package. The main target of our…

Mass-loss from massive stars is fundamental to stellar and galactic evolution and enrichment of the interstellar medium. Reliable determination of mass-loss rate is dependent upon unravelling details of massive star outflows, including…

Determining star cluster distances is essential to analyse their properties and distribution in the Galaxy. In particular it is desirable to have a reliable, purely photometric distance estimation method for large samples of newly…

We report the detection of Cepheid variable stars in the barred spiral galaxy NGC 1365, located in the Fornax cluster, using the Hubble Space Telescope Wide Field and Planetary Camera 2. Twelve V (F555W) and four I (F814W) epochs of…

A fraction of the extreme horizontal branch stars of globular clusters exhibit a periodic light variability that has been attributed to rotational modulation caused by surface spots. These spots are believed to be connected to inhomogeneous…

We present the results of a search for periodic variables within 4078 time-series light curves and an analysis of the period-color plane for stars in the field of the open cluster NGC2301. One hundred thirty-eight periodic variables were…

The search of secondary pulsations is carried out to understand the possible relations among the known parameters of variables of the cluster, NGC 6866. These pulsations arise due to the various ongoing physical phenomena of the variables.…

The first calibrated broadband BVI time-series photometry is presented for the variable stars in NGC 2808, with observations spanning a range of twenty-eight years. We have also redetermined the variability types and periods for the…

We use about 200,000 FGK type main-sequence stars from the LAMOST DR1 data to map the local stellar kinematics. With the velocity de-projection technique, we are able to derive the averaged 3 dimensional velocity and velocity ellipsoids…

The evolution of star clusters is studied using N-body simulations in which the evolution of single stars and binaries are taken self-consistently into account. Initial conditions are chosen to represent relatively young Galactic open…

We present an analysis of J, H, and K time series photometry obtained with the southern 2MASS telescope over a 0.84 x 6 deg^2 region centered near the Orion Nebula Cluster. These data are used to establish the near-infrared variability…

We have studied the stellar main sequence (MS) of the globular cluster NGC2298 using deep HST/ACS observations in the F606W and F814W bands covering an area of 3.4' x 3.4' around the cluster centre or about twice the cluster's half-mass…

We present the results of a photometric survey for variable stars in the field of the nearby globular cluster NGC 6752. The cluster was monitored in 1996 and 1997 for a total of 54 hours with 3 different CCD cameras mounted on the 1.0-m…