Related papers: The effect of activity on stellar temperatures and…
We examine the performance of standard PMS stellar evolution models against the accurately measured properties of a benchmark sample of 26 PMS stars in 13 EB systems. We provide a definitive compilation of all fundamental properties for the…
If magnetic activity in outer stellar atmospheres is due to an interplay between rotation and subsurface convection, as is generally presumed, then one would not expect to observe indicators of activity in stars with T_eff > 8300 K. Any…
The lithium abundances of planet-harbouring stars have been compared with those of open clusters and field stars. Young (chromospherically active) and subgiant stars have been eliminated from the comparison because they are at different…
Observations of the Sun and of Sun-like stars provide access to different aspects of stellar magnetic activity that, when combined, help us piece together a more comprehensive picture than can be achieved from only the solar or the stellar…
We analyze the correlation between starspots and superflares on solar-type stars using observations from the Kepler mission. The analysis shows that the observed fraction of stars with superflares decreases as the rotation period increases…
(Abridged) Eclipsing, spectroscopic double-lined binary star systems (SB2) are excellent laboratories for calibrating theories of stellar interior structure and evolution. We aim to investigate the mass discrepancy in binary stars. We study…
Spectroscopic and eclipsing binary systems offer the best means for determining accurate physical properties of stars, including their masses and radii. The data available for low-mass stars have yielded firm evidence that stellar structure…
The detected exoplanet population displays a dearth of planets with sizes of about two Earth radii, the so-called radius gap. This is interpreted as an evolutionary effect driven by a variety of possible atmospheric mass loss processes of…
The interaction between the magnetic fields of late-type stars and their close-by planets may produce stellar flares as observed in active binary systems. However, in spite of several claims, conclusive evidence is still lacking. We…
The observed radii of M dwarfs in eclipsing binaries exceed predicted radii by ~ 5%. To investigate this anomaly, the structure of low-mass stars irradiated by a close companion is considered. Irradiation modifies the surface boundary…
Recent studies have shown that stellar chromospheric activity, and its effect on convective energy transport in the envelope, is most likely the cause of significant radius and temperature discrepancies between theoretical evolution models…
Precise, high-cadence, long-term records of stellar spectral variability at different temporal scales lead to better understanding of a wide variety of phenomena including stellar atmospheres and dynamos, convective motions, and rotational…
Eclipsing binary stars are gratifying objects because of their unique geometrical properties upon which all important physical parameters such as masses, radii, temperatures, luminosities and distance may be obtained in absolute scale. This…
The orbital properties of stars in the disk are signatures of their formation, but they are also expected to change over time due to the dynamical evolution of the Galaxy. Stellar orbits can be quantified by three dynamical actions, J_r,…
Stellar chromospheric activity serves as a valuable proxy for estimating stellar ages, though its applicable range and accurate functional form are still debated. In this study, utilizing the LAMOST spectra we compiled a catalog of open…
We highlight the importance of eclipsing double-line binaries in our understanding on star formation and evolution. We review the recent discoveries of low-mass and sub-stellar eclipsing binaries belonging to star-forming regions, open…
Using a recent census of flare stars from the Kepler survey, we have explored how flare activity evolves across stellar main sequence lifetimes. We utilize a sample of 347 stars with robust flare activity detections, and which have rotation…
It is argued that apart from the well known dependence of the Am phenomenon on the mass, age (effective temperature, gravity) and rotation there is also a complex dependence on the orbital parameters in binary systems. This is why the…
This chapter reviews the dynamical processes in young stellar clusters. The accretion of gas by individual stars affects the dynamics of the cluster, and the masses of the stars. Dynamical mass segregation cannot explain the degree of mass…
Simulations of the effects of stellar fly-bys on planetary systems in star-forming regions show a strong dependence on subtle variations in the initial spatial and kinematic substructure of the regions. For similar stellar densities, the…