相关论文: The Evolution of Flare Activity with Stellar Age
We wrote and used an automated flare detection Python script to search for super-flares on main-sequence stars of types A, F, G, K, and M in Kepler's long-cadence data from Q0 to Q17. We studied the statistical properties of the occurrence…
We present first results from a new, multiyear, time domain survey of young stars in the North America Nebula complex using the Palomar Transient Factory. Our survey is providing an unprecedented view of aperiodic variability in young stars…
Flares are known to play an important role for the evolution of the atmospheres of young planets. In order to understand the evolution of planets, it is thus important to study the flare-activity of young stars. This is particularly the…
The Sun and stars with low magnetic activity levels, become photometrically brighter when their activity increases. Magnetically more active stars display the opposite behaviour and get fainter when their activity increases. We reproduce…
Context. Considerable effort has been put into using light curves observed by space telescopes such as CoRoT, Kepler and TESS for determining stellar rotation periods. While rotation periods of active stars can be reliably determined, the…
We present two main results, based on the models and the statistical analyses of 1672 U-band flares. We also discuss the behaviours of the white-light flares. In addition, the parameters of the flares detected from two years of observations…
Context. Kepler-17 is a G2V sun-like star accompanied by a transiting planet with a mass of ~2.5 Jupiter masses and an orbital period of 1.486 d, recently discovered by the Kepler space telescope. This star is highly interesting as a young…
Magnetic activity is a ubiquitous feature of stars with convective outer layers, with implications from stellar evolution to planetary atmospheres. Investigating the mechanisms responsible for the observed stellar activity signals from days…
We study the relationship between Galactic location ($R, Z$) and photometric activity for 3.6 million M dwarf stars within 1 kpc of the Sun. For this purpose, we identify 906 unique flare events as a proxy for magnetic activity from the…
We conducted high dispersion spectroscopic observations of 50 superflare stars with Subaru/HDS. These 50 stars were selected from the solar-type superflare stars that we had discovered from the Kepler data. More than half (34 stars) of…
We analyzed the occurrence rates of flares on stars of spectral types K, G, F, and A, observed by Kepler. We found that the histogram of occurrence frequencies of stellar flares is systematically shifted towards a high-energy tail for…
The star formation rate in spiral galaxies is considered to be decreasing continuously with time in a time scale of $10^{9}$ yr. The present star formation activity, on the other hand, shows various degrees among galaxies. We make a new…
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…
Light curves produced by the Kepler mission demonstrate stochastic brightness fluctuations (or "flicker") of stellar origin which contribute to the noise floor, limiting the sensitivity of exoplanet detection and characterization methods.…
Variability is a common characteristic of magnetically active stars. Flaring variability is usually interpreted as the observable consequence of transient magnetic reconnection processes happening in the stellar outer atmosphere. Stellar…
The Kepler space telescope leaves a legacy of tens of thousands of stellar rotation period measurements. While many of these stars show strong periodicity, there exists an even bigger fraction of stars with irregular variability for which…
The study is devoted to search for flare stars among confirmed members of Galactic open clusters using high-cadence photometry from {\it TESS} mission. We analyzed 957 high-cadence light curves of members from 136 open clusters. As a…
Archives of long photometric surveys, like the Kepler database, are a gold mine for studying flares. However, identifying them is a complex task; while in the case of single-target observations it can be easily done manually by visual…
Sun-like stars show intensity fluctuations on a number of time scales due to various physical phenomena on their surfaces. These phenomena can convincingly be studied in the frequency spectra of these stars - while the strongest signatures…
Using data of fast-rotating active dwarf stars in the Kepler database, we perform time-frequency analysis of the light curves in order to search for signs of activity cycles. We use the phenomenon that the active region latitudes vary with…