Related papers: Spatial Inhomogeneity In Solar Faculae
We analyze a series of full-Sun observations, which was performed with the SoHO/SUMER instrument between March and October 1996. Some parameters (radiance, shift and width) of the S VI 93.3 nm, S VI 94.4 nm, and Lyman Epsilon line profiles…
We present results on the structure of the near-surface layers of the Sun obtained by inverting frequencies of high-degree solar modes from "ring diagrams". We have results for eight epochs between June 1996 and October 2003. The…
We have made high-resolution, high-sensitivity dynamic spectra of a sample of strong pulsars at 430 MHz with the Arecibo radiotelescope. For 4 pulsars we find faint but sharply delineated features in the secondary spectra. These are…
Due to non-homogeneous mass distribution and non-uniform velocity rate inside the Sun, the solar outer shape is distorted in latitude. In this paper, we analyze the consequences of a temporal change in this figure on the luminosity. To do…
A new three-dimensional model of the solar photosphere is presented in this paper and made publicly available to the community. This model has the peculiarity that it has been obtained by inverting spectro-polarimetric observations, rather…
Inaccurate modelling of the near-surface layers of solar models causes a systematic difference between modelled and observed solar mode frequencies. This difference---known as the "surface effect" or "surface term"---presumably also exists…
High-resolution imaging observations from the Hinode spacecraft in the CaII H line are employed to study the dynamics of the chromosphere above a sunspot. We find that umbral flashes and other brightenings produced by the oscillation are…
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…
Polar faculae (PFe) are the footpoints of magnetic field lines near the Sun's poles that are seen as bright regions along the edges of granules. The time variation in the number of PFe has been shown to correlate with the strength of the…
The discovery of the solar activity cycle was linked from the outset to the observation of the temporal variability of sunspots, which we know to be the result of complex processes associated with the dynamics of inner layers. Numerous…
Using a simple model based on the characteristics of sunspots and faculae in solar active regions, the effects of surface brightness inhomogeneities on the position of the photocentre of the disk of a solar-like, magnetically active star,…
Commenting the 11-year sunspot cycle, Wolf (1859, MNRAS 19, 85-86) conjectured that "the variations of spot frequency depend on the influences of Venus, Earth, Jupiter, and Saturn". The high synchronization of our planetary system is…
We report time-resolved photoluminescence spectra of point defects in amorphous silicon dioxide (silica), in particular the decay kinetics of the emission signals of extrinsic Oxygen Deficient Centres of the second type from singlet and…
Context. An analysis of the oscillations above sunspots was carried out using simultaneous ground-based and Solar Dynamics Observatory (SDO) observations (SiI 10827A, HeI 10830A, FeI 6173A, 1700A, HeII 304A, FeIX 171A). Aims. Investigation…
The long term study of the Sun is necessary if we are to determine the evolution of sunspot properties and thereby inform modeling of the solar dynamo, particularly on scales of a solar cycle. We aim to determine a number of sunspot…
Birmingham Solar Oscillations Network (BiSON) instruments use resonant scattering spectrometers to make unresolved Doppler velocity observations of the Sun. Unresolved measurements are not homogenous across the solar disc and so the…
The observations of the Sun have been performed over the years, even centuries- Whether are there active longitudes? If yes how stable are they? One of the first The Wilcox Solar Observatory data taken over three cycles N 21, N 22, N 23…
While photospheric magnetic elements appear mainly as Bright Points (BPs) at the disk center and as faculae near the limb, high-resolution images reveal the coexistence of BPs and faculae over a range of heliocentric angles. This is not…
Solar prominences are structures of importance because of their role in polar field reversal. We study the long-term variation of the time latitude distribution of solar prominences in this article. To accomplish this, we primarily used the…
We present observations of a solar quiet region obtained by the ground-based Dutch Open Telescope (DOT), and by instruments on the spacecraft SOHO and TRACE. The observations were obtained during a coordinated observing campaign on October…