Related papers: The radiative-convective gap: fact or fiction?
The predicted width of the upper main sequence in stellar evolution models depends on the empirical calibration of the convective overshooting parameter. Despite decades of discussions, its precise value is still unknown and further…
The Radcliffe Wave has only recently been recognised as a about 3 kpc long coherent gas structure encompassing most of the star forming regions in the solar vicinity. Since its discovery, it has been mainly studied from the perspective of…
We present the 2nd version of the Catalogue of Radial Velocities with Astrometric Data (CRVAD-2). This is the result of the cross-identification of stars from the All-Sky Compiled Catalogue of 2.5 Million Stars (ASCC-2.5) with the General…
We review the main results obtained from our seismic studies of B-type main sequence pulsators, based on the ground-based, MOST, Kepler and BRITE observations. Important constraints on stellar opacities, convective overshooting and rotation…
It is not understood whether long-lived star clusters possess a continuous range of sizes and masses (and hence densities), or if rather, they should be considered as distinct types with different origins. Utilizing the Hubble Space…
Aims: Our aim is to obtain ages that are as accurate as possible for the seven nearby open clusters alpha Per, Coma Ber, IC 2602, NGC 2232, NGC 2451A, NGC 2516, and NGC 6475, each of which contains at least one magnetic Ap or Bp star.…
The (magnetic) chemically peculiar (CP) stars of the upper main sequence are well-suited laboratories for investigating the influence of magnetic fields on the stellar surface because they produce abundance inhomogeneities (spots), which…
NGC 4815 is a populous ~500 Myr open cluster at a Galactocentric radius of 7 kpc observed in the first six months of the Gaia-ESO Survey. Located in the inner Galactic disk, NGC 4815 is an important tracer of the abundance gradient, where…
Context: Open clusters are ideal laboratories to investigate a variety of astrophysical topics, from the properties of the Galactic disc to stellar evolution models. For this purpose, we need to know their chemical composition in detail.…
The elemental abundance distribution of stars encodes the history of the gas-phase abundance in the Milky Way. Without a large, unbiased sample of highly precise stellar ages, the exact timing and nature of this history must be inferred…
We have modeled in detail the evolution of rich open star clusters such as the Pleiades, Praesepe and Hyades, using simulations that include stellar dynamics as well as the effects of stellar evolution. The dynamics is modeled via direct…
A detailed analysis of more than 800 electronic high-resolution spectra of gamma Cas, which were obtained during a time interval of over 6000 days (16.84 yrs) at several observatories, documents the smooth variations in the density and/or…
We observe the brightest member of the Praesepe cluster, Epsilon Cancri, to precisely measure the characteristics of the stars in this binary system, en route to a new measurement of the cluster's age. We present spectroscopic radial…
This paper reports the discovery of new slowly pulsating B-type stars. Based on the photometric, spectral, and astrometric data of TESS, LAMOST, and Gaia surveys, we have found 286 new slowly pulsating B-type stars (SPB stars) and 21…
In our recent catalogue of BY Draconis (BY Dra) variables based on Zwicky Transient Facility data, we found traces of a period gap in the period-colour diagram. We combined our BY Dra database with catalogues from the {\sl Kepler} and K2…
We present three new methods for determining the age of groups of pre-main-sequence stars. The first, creating empirical isochrones allows us to create a robust age ordering, but not to derive actual ages. The second, using the width of the…
The evolution of stars born with a convective core is highly dependent on the efficiency and extent of near core mixing processes, which effectively increases both the core mass and main-sequence lifetime. We investigate to what extent…
Rotation and magnetic activity are intimately linked in main-sequence stars of G or later spectral types. The presence and level of magnetic activity depend on stellar rotation, and rotation itself is strongly influenced by strength and…
Differences in chemical composition among main sequence stars within a given cluster are probably due to differences in their masses and other effects such as radiative diffusion, magnetic field, rotation, mixing mechanisms, mass loss,…
V909 Cas is a little-studied example of a \b{eta} Cep pulsating variable located in the OB association Cas OB8 in the Perseus spiral arm of the Milky Way. Photometric observations in 2016-7 provided 30 new times of pulsation extrema and…