Related papers: Variability survey in the young open cluster IC 18…
CONTEXT: Recent progress in the seismic interpretation of field beta Cep stars has resulted in improvements of the physics in the stellar structure and evolution models of massive stars. Further asteroseismic constraints can be obtained…
Beta Cephei-type variables are early B-type stars that are characterized by oscillations observable in their optical light curves. At least one Beta Cep-variable also shows periodic variability in X-rays. Here we study the X-ray light…
We summarize the properties of the new periodic, small amplitude, variable stars recently discovered in the open cluster NGC 3766. They are located in the region of the Hertzsprung-Russell diagram between \delta\ Sct and slowly pulsating B…
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…
We present the results of the $UBVI_C$ variability survey in the young open cluster NGC 6611 based on observations obtained during 34 nights spanning one year. In total, we found 95 variable stars. Most of these stars are classified as…
We present VI photometry for the open cluster NGC 637 which is located in the Cassiopeia region. Morphology of cluster color-magnitude diagram indicates that it is a young object with age of a few million years. The apparent distance…
The first results are presented of a four-year program dedicated to the CCD observations of Cepheids in the nearby galaxy IC 1613. Since the program was carried out with a relatively small telescope, the Dutch 0.9 m at ESO-La Silla, the…
We report VI CCD photometry of the globular cluster cluster NGC 1851. We aim to study the membership of the variable stars detected in the field of the cluster as listed in the Catalogue of Variable stars in Globular Clusters (CVSGC;…
The detection of magnetic chemically peculiar (CP2) stars in open clusters of the Milky Way can be used to study the influence of different galactic environments on the (non-)presence of peculiarities, which has to be taken into account in…
Variability is a common characteristic of pre-main-sequence stars (PMS). Near-IR variability surveys of young stellar objects (YSOs) can probe stellar and circumstellar environments and provide information about the dynamics of the on going…
We report on the study of the population of B and Be stars in SMC young clusters, performed with the Wide Field Imager in slitless spectroscopic mode at ESO/T2.2m with a filter centered at Halpha. First, we explain the reduction methods we…
The feasibility of using data from the NASA STEREO mission for variable star and asteroseismology studies has been examined. A data analysis pipeline has been developed that is able to apply selected algorithms to the entire database of…
We present a survey of variable stars detected in K2 Campaign 13 within the massive intermediate age ($\sim1$ Gyr) open cluster NGC 1817. We identify a complete sample of 44 red clump stars in the cluster, and have measured asteroseismic…
We used Johnson UBV photometric CCD observations to identify pulsating and other variable stars in the young open cluster NGC 6231. The multi-color information was used to classify pulsating variables, perform frequency analysis, and -…
We present preliminary results of the first near-infrared variability study of the Arches cluster, using adaptive optics data from NIRI/Gemini and NACO/VLT. The goal is to discover eclipsing binaries in this young (2.5 $\pm$ 0.5 Myr),…
We present deep wide-field optical CCD photometry and mid-infrared Spitzer/IRAC and MIPS 24micron data for about 100,000 stars in the young open cluster IC 1805. The members of IC 1805 were selected from their location in the various…
Open clusters and associations are groups of young stars, respectively bound and unbound, that share the same origin and disperse over time into the galactic field. As such, their formation and evolution are the key to understand the origin…
The Quintuplet cluster is one of the most massive star clusters in the Milky Way, situated very close to the Galactic center. We present a new search for variable stars in the vicinity of the cluster, using the five-year database of the…
We have conducted a large-scale survey of the northern plane using Kiso Wide Field Camera attached to Schmidt telescope at Kiso observatory. The KISOGP (KWFC Intensive Survey of the Galactic Plane) project have made 40-70 epoch observations…
We present preliminary results of the first near-infrared variability study of the Arches cluster, using adaptive optics data from NIRI/Gemini and NACO/VLT. The goal is to discover eclipsing binaries in this young (2.5 +- 0.5 Myr), dense,…