Related papers: A representative sample of Be Stars I: Sample Sele…
Rotation is a critical physical process operating in the formation of Am stars. There is a strong correlation between low-velocity rotation and chemical peculiarity. However, the existence of many non-CP slow rotators challenges the…
A new investigation of the variability of the SPB-type star 53 Per is presented. The analysis of the BRITE photometry allowed us to determine eight independent frequencies and the combination one. Five of these frequencies and the…
We have searched for nonastrophysical emission lines in the optical spectra of 577 nearby F, G, K, and M main-sequence stars. Emission lines of astrophysical origin would also have been detected, such as from a time--variable chromosphere…
We present an Echelle+CCD, high S/N, high resolution (R = 20\,000) spectroscopic atlas of 108 well-known objects representative of the most common types of peculiar and variable stars. The wavelength interval extends from 4600 to 9400 Ang,…
New space missions (e.g., NASA-TESS and ESA-PLATO) will perform an analysis of bright stars in large fields of the celestial sphere searching for extraterrestrial planets. Asteroseismic observations will search for exoplanet-hosting stars…
An analysis of solid-state features in infrared spectra of 46 Herbig Ae/Be stars is presented. The presence of solid-state emission bands is compared to other indicators of circumstellar material, such as Halpha emission, optical…
Galactic globular clusters have been pivotal in our understanding of many astrophysical phenomena. Here we publish the extracted stellar parameters from a recent large spectroscopic survey of ten globular clusters. A brief review of the…
We present the results of a spectroscopic investigation of 108 nearby field B-stars. We derive their key stellar parameters, $V \sin i$, $T_{\rm eff}$, $\log g$, and $\log g_{\rm polar}$, using the same methods that we used in our previous…
Star clusters are privileged laboratories for studying the evolution of massive stars (OB stars). One particularly interesting question concerns the phases, during which the classical Be stars occur, which unlike HAe/Be stars, are not…
About 22000 Kepler stars and nearly 60000 TESS stars from sectors 1-24 have been classified according to variability type. A large proportion of stars of all spectral types appear to have periods consistent with the expected rotation…
We analyzed the star HD 171219, one of the relatively bright Be stars observed in the seismo field of the CoRoT satellite, in order to determine its physical and pulsation characteristics. Classical Be stars are main-sequence objects of…
We present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars. A majority of these stars…
We present the results of a search for Be stars in six fields centered on the young clusters NGC 330 and NGC 346 in the SMC, and NGC 1818, NGC 1948, NGC 2004 and NGC 2100 in the LMC. Be stars were identified by differencing R band and…
In recent years the idea, first formulated many decades ago, that the Be phenomenon could be causally related to the duplicity of Be stars, has been repeatedly reconsidered from various perspectives. It is important, therefore, to have…
We derive single-epoch radial velocities for a sample of 56 B-type stars members of the subgroups Upper Scorpius, Upper Centaurus Lupus and Lower Centaurus Crux of the nearby Sco-Cen OB association. The radial velocity measurements were…
Uncertainties in stellar structure and evolution theory are largest for stars undergoing core convection on the main sequence. A powerful way to calibrate the free parameters used in the theory of stellar interiors is asteroseismology,…
We present HST/STIS Ultraviolet spectra of the six known Ofpe/WN9 stars (``slash stars'') in M33. These stars were selected for showing the characteristics of the Ofpe/WN9 class from previous optical ground-based spectroscopy. The UV…
The complexity of composite spectra of close binary star system makes study of the spectra of their component stars extremely difficult. For this reason there exists very little information on the photospheric chemical composition of stars…
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…
Context. Stellar physical properties of star clusters are poorly known. Aims. Our goals are to perform a spectrophotometric study of the B star population in open clusters to derive accurate stellar parameters, search for the presence of…