相关论文: General Model for Light curves of Chromosphericall…

We present more than 1000-day long photometry of EY Draconis in BV(RI)C passbands. The changes in the light curve are caused by the spottedness of the rotating surface. Modelling of the spotted surface shows that there are two large active…

We present Kepler light curves and optical spectroscopy of twenty X-ray bright stars located in the Kepler field of view. The stars, spectral type FK, show evidence for rapid rotation including chromospheric activity 100 times or more above…

The first micro-lensing event discovered towards the Small Magellanic Cloud by the MACHO collaboration (Alcock et al. 1997b) had a very long time scale, t_0 = 123 days. The EROS collaboration (Palanque-Delabrouille et al. 1997) discovered a…

We investigate the photometric modulation induced by magnetic activity cycles and study the relationship between rotation period and activity cycle(s) in late-type (FGKM) stars. We analyse light-curves spanning up to 9 years of 125 nearby…

This study depends on KIC 9641031 eclipsing binary system with a chromospherically active component. There are three type variations, such as geometrical variations due to eclipses, sinusoidal variations due to the rotational modulations…

We investigate the spot activity of the young chromospherically active main sequence star LQ Hya. Our aims are to identify possible active longitudes, estimate the differential rotation and study long and short term changes in the activity.…

Studying RS CVn binaries is challenging, because in addition to spot activity, other effects such as mass transfer between the components and gravitational distortion of their spherical forms may distort their light curves. Such effects…

Luminous X-ray stars are very often found in visual double or multiple stars. Binaries with periods of a few days possess the highest degree of coronal X-ray activity among regular, non-relativistic stars because of their fast, tidally…

We have analyzed Kepler light curves for 849 stars with T_eff < 5200 K from our Cycle 1 Guest Observer program. We identify six new eclipsing binaries, one of which has an orbital period of 29.91 d, and two of which are probably W UMa…

Obtaining measurements of chromospheric and photometric activity of stars with near-solar fundamental parameters and rotation periods is important for a better understanding of solar-stellar connection. We select a sample of 2603 stars with…

Abstract We investigate a short-period W UMa binary KIC 9026766 with an orbital period of 0.2721278 days in the Kepler field of view. By using an automated q-search for the folded light curve and producing a synthetic light curve for this…

Close binary systems often show linear polarization varying over the binary period, usually attributed to light scattered from electrons in circumstellar clouds. One of the brightest close binary systems is Spica (Alpha Virginis) consisting…

We study the time variations of the cycles of 20 active stars based on decades-long photometric or spectroscopic observations. A method of time-frequency analysis, as discussed in a companion paper, is applied to the data. Fifteen stars…

In binary systems with a strongly misaligned disk, the central binary stars can travel a significant vertical distance above and below the disk's orbital plane. This can cause large changes in illumination of the disk over the course of the…

Observations of various solar-type stars along decades revealed that they can have magnetic cycles, just like our Sun. An investigation of the relation between their cycle length and rotation period can shed light on the dynamo mechanisms…

We present an analysis of the starspot evolution, the surface differential rotation (SDR), the correlation between chromospheric activity indicators and the spatial connection between chromospheric and photospheric activities on the active…

During the solar magnetic activity cycle the emergence latitudes of sunspots change, leading to the well-known butterfly diagram. This phenomenon is poorly understood for other stars as starspot latitudes are generally unknown. The related…

We show that the flip-flop transitions in X-ray binaries (rapid cycling between different spectral states which are sometimes seen near the global state transition) show a series of analogies to the changing state phenomena (rapid changes…

In a search of proper motion catalogs for common proper motion stars in the field of the Kepler spacecraft I identified 93 likely binary systems. A comparison of their rotation periods is a test of the gyrochronology concept. To find their…

Stellar activity is fundamental to stellar evolution and the formation and habitability of exoplanets. The interaction between convective motions and rotation in cool stars results in a dynamo process that drives magnetic surface activity.…