The two-dimensional temperature distribution in a highly structured sunspot and in two small umbrae is determined from a three-colour photometry in narrow spectral continua. Disturbing influences from the earth’s atmosphere are removed by speckle masking techniques, yielding a spatial resolution limited by the telescope’s aperture. The corresponding colour temperatures are consistent over a ran...

In order to study umbral oscillations, running penumbral waves and the relationship between them, we analyzed CCD, high resolution, sunspot observations obtained at center and the wings of the Hα line and the Fe I 5576 Å line. The UBF filter was used in order to produce high cadence sequences of filtergrams. Images were processed to remove the sharp intensity gradient between the umbra and the ...

in this research we described the effective hamiltonian theory and applied this theory to the calculation of current-current (q1,2) and qcd penguin (q3,…,6) c quark decay rates. we calculated the decay rates of semileptonic and hadronic of charm quark in the effective hamiltonian theory. we investigated the decay rates of d meson decays according to spectator quark model (sqm) for the calculati...

Context. Upflows in the corona are of importance, as they may contribute to solar wind. There has been considerable interest upflows from active regions (ARs). The coronal that seen at edges have elemental composition and can slow sources challenging determine because be multiple, spatial resolution previous observations is not yet high enough. Aims. In this article, we analyse AR 12960 unusual...

Let G be a Hamiltonian graph. A factor F of G is called a Hamiltonian factor if F contains a Hamiltonian cycle. In this paper, two sufficient conditions are given, which are two neighborhood conditions for a Hamiltonian graph G to have a Hamiltonian factor. Keywords—graph, neighborhood, factor, Hamiltonian factor.

From a kinematical point of view, the geometrical information of hamiltonian chaos is given by the (un)stable directions, while the dynamical information is given by the Lyapunov exponents. The finite time Lyapunov exponents are of particular importance in physics. The spatial variations of the finite time Lyapunov exponent and its associated (un)stable direction are related. Both of them are f...