Related papers: Stellar activity, differential rotation, and exopl…
We present the results of numerical experiments to assess degeneracies in lightcurve models of starspots. Using synthetic lightcurves generated with the Cheetah starspot modeling code, we explore the extent to which photometric light curves…
A detailed understanding of the physics of star and planet formation requires study of individual objects as well as statistical assessment of global properties and evolutionary trends. Observational investigations of circumstellar material…
The impact of rotation on the properties of low-mass stars at different evolutionary stages is first described by discussing the properties of stellar models computed with shellular rotation. The observational constraints that are currently…
Due to be launched late 2026, the PLATO mission will bring the study of main-sequence solar-type and low-mass stars into a new era. In particular, PLATO will provide the community with a stellar sample with solar-type oscillations and…
Transits of exoplanets across cool stars contain blended information about structures on the stellar surface and about the planetary body and atmosphere. To advance understanding of how this information is entangled, a surface-flux…
Stellar activity has a particularly strong influence on planets at small orbital distances, such as close-in exoplanets. For such planets, we present two extreme cases of stellar variability, namely stellar coronal mass ejections and…
While it may seem counterintuitive that X-ray astronomy should give any insights into low-temperature planetary systems, planets orbit stars whose magnetized surfaces divert a small fraction of the stellar energy into high energy products:…
Planets interact with their host stars through gravity, radiation and magnetic fields, and for those giant planets that orbit their stars within ~10 stellar radii (~0.1 AU for a sun-like star), star-planet interactions (SPI) are observable…
By using the LAMOST time-domain survey data, we study stellar activities based on the $\rm{H_{\alpha}}$ lines for about 2000 stars in four $K$2 plates. Two indices, $R_{\rm{H\alpha}}^{'}$ and $R_{\rm{H\alpha}}^{+}$, are computed from LAMOST…
Young and active stars generally have regular, almost sinusoidal, patterns of variability attributed to their rotation, while the majority of older and less active stars, including the Sun, have more complex and non-regular light-curves…
We investigate the temporal spot evolution of the K-giant component in the RS CVn-type binary system $\zeta$\,Andromedae to establish its surface differential rotation. Doppler imaging is used to study three slightly overlapping…
Long-term photometric measurements in a sample of ultrashort-period (P~0.5 days or less) single and binary stars of different interior structures are analysed. A loose correlation exists between the rotational rate and cycle lengths of…
The stable oscillations of pulsating stars can serve as accurate timepieces, which may be monitored for the influence of exoplanets. An external companion gravitationally tugs the host star, causing periodic changes in pulsation arrival…
In this short paper, we study the photometric precision of stellar light curves obtained by the CoRoT satellite in its planet finding channel, with a particular emphasis on the timescales characteristic of planetary transits. Together with…
Rotation has a number of important effects on the evolution of stars. Apart from structural changes because of the centrifugal force, turbulent mixing and meridional circulation caused by rotation can dramatically affect a star's chemical…
Extrasolar planets on eccentric short-period orbits provide a laboratory in which to study radiative and tidal interactions between a planet and its host star under extreme forcing conditions. Studying such systems probes how the planet's…
Measuring starspot temperatures is crucial for understanding stellar magnetic activity, as it affects stellar brightness variations, influences exoplanet transit measurements, and provides constraints on the physical conditions and energy…
Context. We present the discovery of two transiting extrasolar planets by the satellite CoRoT. Aims. We aim at a characterization of the planetary bulk parameters, which allow us to further investigate the formation and evolution of the…
Stars are changing entities in a constant evolution during their lives. At non-secular time scales (from seconds to years) the effect of dynamical processes such as convection, rotation, and magnetic fields can modify the stellar…
Oscillations detected on the solar surface provide a unique possibility for investigations of the interior properties of a star. Through major observational efforts, including extensive observations from space, as well as development of…