相关论文: Spot Sizes on Sun-like Stars

The latitudinal distribution of starspots deviates from the solar pattern with increasing rotation rate. Numerical simulations of magnetic flux emergence and transport can help model the observed stellar activity patterns and the associated…

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 number of satellites on low orbit has dramatically increased over the past years, raising concerns among the astronomical community about their impact on observations. Spectroscopic observations represent a large fraction of…

Major solar flares are prone to occur in active region atmospheres associated with large, complex, dynamically-evolving sunspots. This points to the importance of monitoring the evolution of starspots, not only in visible but also in ultra…

In recent years, analyses of eclipsing binary systems have unveiled differences between the observed fundamental properties of low-mass stars and those predicted by stellar structure models. Particularly, radius and effective temperatures…

Our understanding of the structure and dynamics of stellar coronae has changed dramatically with the availability of surface maps of both star spots and also magnetic field vectors. Magnetic field extrapolations from these surface maps…

We present a global study of low mass, young stellar object (YSO) surface densities (Sigma) in nearby (< 500 pc) star forming regions based on a comprehensive collection of Spitzer Space Telescope surveys. We show that the distribution of…

abridged: We use a complete sample of about 140,000 galaxies from the Sloan Digital Sky Survey (SDSS) to study the size distribution of galaxies and its dependence on their luminosity, stellar mass, and morphological type. The large SDSS…

Planetary transits provide a unique opportunity to investigate the surface distributions of star spots. Our aim is to determine if, with continuous observation (such as the data that will be provided by the Kepler mission), we can in…

Frequency analysis of long-term ultra-precise photometry can lead to precise values of rotation frequencies of rotating stars with ``hump and spike'' features in their periodograms. Using these features, we computed the rotation frequencies…

In many active stars the spots concentrate on two permanent active longitudes which are 180 degrees apart. In some of these stars the dominant part of the spot activity changes the longitude every few years. This so-called flip-flop…

High degree solar mode frequencies as measured by ring diagrams are known to change in the presence of the strong magnetic fields found in active regions. We examine these changes in frequency for a large sample of active regions analyzed…

We compare the zonal flow pattern in subsurface layers of the Sun with the distribution of surface magnetic features like sunspots and polar faculae. We demonstrate that in the activity belt, the butterfly pattern of sunspots coincides with…

Aims: Stellar activity may complicate the analysis of high-precision radial-velocity spectroscopic data when looking for exoplanets signatures. We aim at quantifying the impact of stellar spots on stars with various spectral types and…

Close encounters between stars in star forming regions are important as they can perturb or destroy protoplanetary discs, young planetary systems, and stellar multiple systems. We simulate simple, viralised, equal-mass $N$-body star…

On the Sun, the rotation periods of individual sunspots not only trace the latitude dependence of the surface rotation rate, but also provide clues as to the amount of subsurface fluid shear. In this paper we present the first measurements…

What else can be said about star formation rate indicators that has not been said already many times over? The `coming of age' of large ground-based surveys and the unprecedented sensitivity, angular resolution and/or field-of-view of…

In this paper the longitudinal and latitudinal spatial distribution of macrospicules is examined. We found a statistical relationship between the active longitude determined by sunspot groups and the longitudinal distribution of…

Context. CoRoT light curves have an unprecedented photometric quality, having simultaneously a high signal-to-noise ratio, a long time span and a nearly continuous duty-cycle. Aims. We analyse the light-curves of four bright targets…

The sunspot number is analyzed by using detailed sunspot data, including aspects of observability, sunspot sizes, and proper identification of sunspot groups as discrete entities of the solar activity. The tests show that besides the…