Related papers: Testing the recovery of stellar rotation signals f…
We utilize Kepler data to study the precision differential photometric variability of solar-type and cooler stars at different timescales, ranging from half an hour to 3 months. We define a diagnostic that characterizes the median…
(Abridged) We perform a detailed study of the main optical activity indicators (Ca II H & K, Balmer lines, Na I D$_{\rm 1}$ D$_{\rm 2}$, and He I D$_{\rm 3}$) measured for the Sun using the data provided by the HARPS-N solar-telescope feed…
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…
We present an analysis of the starspots on the active M4 dwarf GJ 1243, using four years of time series photometry from Kepler. A rapid $P = 0.592596\pm0.00021$ day rotation period is measured due to the $\sim$2.2\% starspot-induced flux…
The Planetary Transits and Oscillations of stars mission (PLATO) will allow us to measure surface rotation and monitor photometric activity of tens of thousands of main sequence solar-type and subgiant stars. This paper is the first of a…
Starspots and their movements on stellar surfaces enable investigating the mechanisms of stellar magnetic activity. Information on the spot distribution and differential rotation provide important constraints for the behaviour of stellar…
The light curves of old G-dwarfs obtained in the visible and near-infrared wavelength ranges are highly irregular. This significantly complicates the detectability of the rotation periods of stars similar to the Sun in large photometric…
The study of stellar activity is important because it can provide new constraints for dynamo models, when combined with surface rotation rates and the depth of the convection zone. We know that the dynamo mechanism, which is believed to be…
The Kepler mission has been providing high-quality photometric data leading to many breakthroughs in the exoplanet search and in stellar physics. Stellar magnetic activity results from the interaction between rotation, convection, and…
In order to understand stellar evolution, it is crucial to efficiently determine stellar surface rotation periods. An efficient tool to automatically determine reliable rotation periods is needed when dealing with large samples of stellar…
The TESS mission delivers time-series photometry for millions of stars across the sky, offering a probe into stellar astrophysics, including rotation, on a population scale. However, light curve systematics related to the satellite's…
We present a preliminary analysis of the cool pulsating white dwarf GD 1212, enabled by more than 11.5 days of space-based photometry obtained during an engineering test of the two-reaction-wheel-controlled Kepler spacecraft. We detect at…
Stellar activity cycles reveal continuous relaxation and induction of magnetic fields. The activity cycle is typically traced through the observation of cyclic variations in total brightness or Ca H&K emission flux of stars, as well as…
For seven decades, the widely held view has been that the formation, the migration and the decay of short-lived starspots explain the constantly changing light curves of chromospherically active stars. Our hypothesis is that these deceptive…
Light curves of solar-like stars are known to show highly irregular variability. As a consequence, standard frequency analysis methods often fail to detect the correct rotation period. Recently, Shapiro et al. (2020) showed that the periods…
Analyzing the available photometry from the Kepler satellite and other databases, we performed detailed light curve modeling of 10 eclipsing binary systems that were found to exhibit a periodic modulation of their orbital periods. All of…
We carried out numerical experiments on the evaluation of the possibilities of obtaining the information about brightness distributions for the components of eclipsing variables from the data of high-precision photometry expected for…
Accounting for stellar activity is a crucial component of the search for ever-smaller planets orbiting stars of all spectral types. We use Doppler imaging methods to demonstrate that starspot induced radial velocity variability can be…
We present a method that utilizes autocorrelation functions from long-term precision broadband differential light curves to estimate the average lifetimes of starspot groups for two large sample of Kepler stars: stars with and without…
Cross-correlation of consecutive Doppler images is one of the most common techniques used to detect surface differential rotation (hereafter DR) on spotted stars. The disadvantage of a single cross-correlation is, however, that the expected…