Downflows on the solar surface are suspected to play a major role in dynamics of convection zone, at least its outer part. We investigate existence long-lasting downflows whose effects influence interior Sun but also layers. study sets Dopplergrams and magnetograms observed with Solar Dynamics Observatory Hinode spacecrafts an magnetohydrodynamic (MHD) simulation. All aligned sequences, which w...

History has the power to expose the origin and evolution of scientific ideas. How did humanity come to visualize the Sun as a gaseous plasma? Why is its interior thought to contain blackbody radiation? Who were the first people to postulate that the density of the solar body varied greatly with depth? When did mankind first conceive that the solar surface was merely an illusion? What were the f...

High-cadence, high-resolution magnetograms have shown that the quiet-Sun photosphere is very dynamic in nature. It is comprised of discrete magnetic fragments which are characterized by four key processes – emergence, coalescence, fragmentation and cancellation. All of this will have consequences for the magnetic field in the corona above. The aim of this study is to gauge the effect of the beh...

In this talk I presented and discussed our unexpected detection of water vapor in the disk-averaged spectrum of the K2IIIp red giant Arcturus [for details, see Ryde et al. (2002)]. Arcturus, or α Boötes is, with its effective temperature of 4300 K, the hottest star yet to show water vapor features. We argue that the water vapor is photospheric and that its detection provides us with new insight...

We present optical spectropolarimetric observations of Type Ic supernova (SN) 2007gr with Subaru telescope at 21 days after the maximum brightness (∼ 37 days after the explosion). Non-zero polarization as high as ∼ 3 % is observed at the absorption feature of Ca ii IR triplet. The polarization of the continuum light is ∼ 0.5% if we assume an interstellar polarization (ISP) with which SN photosp...

Using the data observed by the Solar Optical Telescope/Spectro-Polarimeter aboard the Hinode satellite, the horizontal and vertical fields are derived from the wavelength-integrated measures of Zeeman-induced linear and circular polarizations. The quiet intranetwork regions are pervaded by horizontal magnetic elements. We categorize the horizontal intranetwork magnetic elements into two types: ...

The study of magnetic connectivity in the solar corona reveals a need to generalize the field line mapping technique to arbitrary geometry of the boundaries and systems of coordinates. Indeed, the global description of the connectivity in the corona requires the use of the photospheric and solar wind boundaries. Both are closed surfaces and therefore do not admit a global regular system of coor...

Here we report on observations of the three-dimensional structure of a sunspot magnetic field from the photosphere to the chromosphere, obtained with the new visible/infrared spectro-polarimeter SPINOR. The observations, interpreted with a non-LTE modeling technique, reveal a surprisingly complex topology with areas of opposite-sign torsion, suggesting that flux-ropes of opposite helicities may...

Combining a variety of data with radiation hydrodynamic simulations, we examine the heating of the Sun’s internetwork chromosphere and the hypothesis that the chromospheric ‘‘ basal ’’ emission arises because of acoustic wave dissipation. We focus on the 2s 2p2 2D 2s22p 2Po multiplet of C ii near 1335 Å, whose basal level of chromospheric emission has been reliably determined for stars and the ...