Related papers: Prospects for the ensemble asteroseismology in you…

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…

In a sample of six young open clusters we investigated 1753 objects using the narrow band, three filter Delta a photometric system resulting in the detection of eleven bona-fide magnetic chemically peculiar (CP) stars and five Be or…

Open clusters offer us the means to study stellar properties in samples with well-defined ages and initial chemical composition. Here we present a survey of projected rotational velocities for a large sample of mainly B-type stars in young…

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 report results of our analysis of the Kepler superaperture LC data of the open cluster NGC6791 to search for pulsating sdB stars. We checked all pixels and we found only three sdB stars to be pulsating, KIC2569576 (B3), KIC2438324 (B4)…

We present here the results of our research for B-type pulsators in low metallicity environments, searching for short-term periodic variability in a large sample of B and Be stars in the Magellanic Clouds (MC), for which the fundamental…

We present preliminary results of the photometric variability search in the field of view of the young open cluster NGC 457. We find over 60 variable stars in the field, including 25 pulsating or candidate pulsating stars.

As many as 10\% of OB-type stars have global magnetic fields, which is surprising given their internal structure is radiative near the surface. A direct probe of internal structure is pulsations, and some OB-type stars exhibit pressure…

The main aim of this paper is to study the astrophysical behavior of open clusters' properties along the Milky Way Galaxy. Near-IR JHK (2MASS) photometry has been used for getting a homogeneous Catalog of 263 open clusters' parameters,…

We recently discovered a large number of highly active Be stars in the open cluster NGC 3766, making it an excellent location to study the formation mechanism of Be star disks. To explore whether similar disk appearances and/or…

Asteroseismology of member pulsators provides a robust physical constraint on cluster parameters by linking internal stellar structures to the global properties of the host cluster. However, the parameters of NGC 1647 remains poorly…

A long-term project, aiming at systematic search for variable stars in Galactic Open Clusters, was started at the Geneva Observatory in 2002. We have been observing regularly a sample of twenty-seven Galactic Open Clusters in the U, B, V…

We present a spectroscopic study of 150 Classical Be stars in 39 open clusters using medium resolution spectra in the wavelength range 3800 - 9000 \AA. One-third of the sample (48 stars in 18 clusters) has been studied for the first time.…

We present a study based on more than 2500 uvby-measurements collected on HD 172189, a new eclipsing binary system with a Delta Sct-type pulsating component that belongs to the open cluster IC 4756. The great interest of this object lies in…

We conducted a survey of open clusters within 1 kpc from the Sun using the astrometric and photometric data of the Gaia Data Release 2. We found 655 cluster candidates by visual inspection of the stellar distributions in proper motion space…

Asteroseismic modelling of isolated star presents significant challenges due to the difficulty in accurately determining stellar parameters, particularly the stellar age. These challenges can be overcomed by observing stars in open…

The BRITE constellation of nanosatellites observes very bright stars to perform seismology. We have set up a spectropolarimetric survey of all BRITE targets, i.e. all ~600 stars brighter than V=4, with Narval at TBL, ESPaDOnS at CFHT and…

Very young open clusters are ideal places to study the X-ray properties of a homogeneous population of early-type stars. In this respect, the IC1805 open cluster is very interesting as it hosts the O4If$^+$ star HD15570 thought to be in an…

To improve our comprehension of the beta Cephei stars, we set up a photometric multi-site campaign on the open cluster NGC 884 (Chi Persei). Thirteen telescopes joined the 2005-2007 campaign which resulted in almost 78000 CCD frames. We…

We performed the optical spectroscopy of 16 classical Be stars in 11 open clusters older than 100 Myr. Ours is the first spectroscopic study of classical Be stars in open clusters older than 100 Myr. We found that the H alpha emission…