To obtain the wave characteristics of hot magnetized plasma, requires investigating a complete dispersion equation describing the oscillations of magnetized plasma, of the form \begin{equation} a+(\omega ^2/k^2c^2)b+(\omega ^4/k^4c^4)c_0=0. \end{equation} Here, \begin{center} $a=(k_{\bot }^2/k^2)\varepsilon _{xx}+(k_z^2/k^2)\varepsilon_{zz}+2(k_{\bot }k_z/k^2)\varepsilon _{xz}$, \end{center} \begin{center} $b=-\varepsilon _{xx}\varepsilon _{zz}+\varepsilon_{xx}^2-(k_z^2/k_{}^2) (\varepsilon _{yy}\varepsilon_{zz}+\varepsilon _{yz}^2)-(k_{\bot }^2/k^2) (\varepsilon_{xx}\varepsilon _{yy}+\varepsilon _{xy}^2)\nonumber +2(k_{\bot}k_z/k^2)(\varepsilon _{xy}\varepsilon _{yz}-\varepsilon_{xz}\varepsilon _{zy})$,\end{center}\begin{center}$c_0=\varepsilon _{zz}(\varepsilon _{xx}\varepsilon_{yy}+\varepsilon _{xy}^2)+\varepsilon _{xx}\varepsilon_{yz}^2-\varepsilon _{yy}\varepsilon _{xz}^2+2\varepsilon_{yz}^{}\varepsilon _{xz}\varepsilon _{xy}$,\vspace*{4pt}\end{center} ω is the complex frequency of the wave, k is the wave number, c is the velocity of light in a vacuum, $k_z$ is the longitudinal (with respect to the magnetic field) wave vector component, $k_{\bot}$ is the transverse wave vector component, and $\varepsilon_{ij}$ stands for the components of the dielectric tensor.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We report on chromospheric oscillations studied with 15 sec cadence observations obtained at a wavelength of 3.5 mm with the Berkeley-Illinois-Maryland Array (BIMA). Different solar structures, including active and quiet-Sun regions, are analyzed. We compare the high-resolution millimeter 2-D images with Ca II K line images from Big Bear Solar Observatory. Using Fourier and wavelet time series analysis techniques we find signatures of intensity oscillations with periods in the range of 2-7 minutes. We discuss the results in the context of the dynamical model of the solar atmosphere by Carlsson & Stein (1995, 1997).To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Archival full disk observations of the central depth of Mn 539.467, a photospheric line, have been found to correlate with chromospheric Ca K intensity. In this paper we present spectroheliograms taken in Mn I 539.467 and 542.32 nm lines and other nearby lines to see if the other photospheric lines show chromospheric structures. We see both Mn images and also Si I 542.118 mimic magnetograms the similar way, while strong Fe and Ti lines only faintly reveal magnetic features, and weak Fe lines of comparable strength to Mn show nothing.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We provide an observational proof of the existence of the global sausage mode oscillations in a flaring loop studying a microwave burst with quasi-periodical pulsations observed with the Nobeyama Radioheliograph (NoRH).To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

This paper presents the results of the active region observations in red coronal line ($\lambda = 6374 \stackrel{\circ}{\rm A}$). The analysis was made of the dependence of the profile parameters of the red coronal line on the exposition value.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Changes in Total Solar Irradiance (TSI) were studied both in time-frequency and in time-longitude aspects. The continuous wavelet analysis of TSI composite time series (Fröhlich & Lean 1998; Willson & Mordvinov 2003) revealed that the energy of thermomagnetic disturbances due to sunspots and faculae cascades into the magnetic network and facular macrostructure. The time-longitude analysis revealed large-scale patterns of radiative excesses in solar atmosphere. These patterns are organized into 2- and 4- sector structures exhibiting the effects of both activity complexes and magnetically active longitudes. Large-scale patterns with radiative excess display a facular macrostructure. These temperature patterns are causally related to long lived magnetic fields of the Sun. During activity cycles 21–23 the patterns with radiative excess tend to be concentrated around the active longitudes which are centered at about 60° and 230° in the Carrington system (Benevolenskaya et al. 1999; Mordvinov & Willson 2003).To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

A sufficiently thick and dense flaring magnetic loop is shown to be able to support global sausage magnetoacoustic modes. The oscillation period of this mode, calculated in the straight cylinder approximation, is determined by the length of the loop, not by its diameter, as it has previously been assumed. For the existence of this mode, the ratio of the loop length to its diameter is to be less than about a half of the square root of the density contrast ratio. This mode has a maximum of the magnetic field perturbation at the loop apex and nodes at the footpoints. We demonstrate that the 14-17 sec quasi-periodical pulsations of microwave emission, oscillating in phase at a loop apex and at its legs, as observed with the Nobeyama Radioheliograph, are interpreted in terms of the global sausage mode.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We represent results of experiments on investigation of solar wind plasma by the method of radio sounding, when the signal from the radio source paths through the solar wind plasma and then it's received at ground-based radiointerferometer.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The CCD spectroheliograph-magnetograph is a focal plane ancillary instrument for Pulkovo horizontal solar telescope ACU-5. The instrument is placed at an exit port of an isothermal high-resolution diffraction-grating spectrograph. The modified Leighton optical scheme for registration of sunspot magnetic fields is used. The instrument provides obtaining FITS digital video cards of radial velocities, magnetic fields and spectroheliogram in any line of spectral region 3900A - 11000A. The time of obtaining of one video card by the size 91″ $\times$154″ is equal 10.24sec. The angular resolution of the instrument is 0″.8; spectral resolution is 0.01-0.03A. There is remote access to a solar telescope in real time on the basis of Internet - process engineerings.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Geomagnetic activity variations are closely related to the global magnetic field of the Sun and could serve as useful proxies to reconstruct the solar wind history and evolution of the inner heliosphere. Historical geomagnetic records reveal trends in the solar wind and interplanetary magnetic field variability resulting from topological changes of the heliospheric current sheet and solar corona viewed from the Earth. Predictions of the solar cycle based on geomagnetic trends are presented.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We compare the enhanced temperature regions (ETRs) in the millimeter radio emission of the Sun with other manifestation of solar activity during 10 days in 1997, 1998, 2000 and 2003. The radio observations at 37 GHz and 87 GHz were done with the Metsahovi Radio Telescope (Finland). We concentrate on the weak ETRs with no discernible connection to sunspots, and in some case compare their properties with those which do have a clear connection to sunspots. Extended observations at 37 GHz in July 2003 enable us to measure the lifetimes of some weak ETRs and also their brightness temperature variations. The 37/87 GHz full-disk radio intensity contours are superposed on $CaII (k_{3})$ and $H_{\alpha}$ images observed with the Meudon Spectroheliograph (France) for comparing the optical positions and the brightness characteristics of these regions. A similar comparison is also made with the SOHO/MDI full-disk magnetograms and SOHO/EIT images. There appear to be two different classes of weak ETRs. One class is connected with local brightness features seen in $CaII (k_{3})$, $H_{\alpha}$ images and magnetograms. The other class is connected with so-called minor brightness features.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Solar sporadic radio emission takes place in a wide range of time scales; from milliseconds to days. Researches have been conduced mainly to explain the behavior of radio emission in specific time scales and lately to millisecond spikes research has been devoted a lot of papers.

In this work we pay attention to the characteristics of millisecond spikes in relation to the general activity in which they are included, processes with very different time scales.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We show that the latitudinal distribution of the coronal bright points (BPs) changes between the solar minimum and the rising phase of solar cycle 23. In 1996, the number of BPs peaks near the disk center. In 1998, the distribution shows bands of increased BPs' number at the ARs' latitudes.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present the preliminary results of study of the coronal bright points (BPs) using the SoHO/EIT data. We show that the number of BPs in quiet Sun areas does not vary between 1996 and 1997. In 1998 the BPs number (full disk) increases by about 20%.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The purpose of this investigation is a comparison of long-wave radiobursts, registered in the range of frequencies 100-1500 kHz with multi-channel radiometer AKR-X installed on INTERBALL-1, and hard X-ray fluxes in energy range 14-93 keV observed by YOHKOH/HXT during solar flares. We selected several events with flares of importance X and M, for which there were simultaneous observations in the hard X-ray and radio ranges during the impulsive phase of a flare. The temporal profiles of radiobursts are characterized by the rapid frequency drift, typical to the radiobursts of III type, caused by the motion of energetic electrons accelerated in the flare and which are spreading at the corona and interplanetary medium, up to the Earth orbit.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Preliminary analysis of spectra collected with the RESIK Bragg bent crystal X-ray spectrometer aboard CORONAS-F indicates the presence of many spectral features which until recently were unidentified. We present RESIK spectra in which the H-like Cl XVII Ly$\alpha$ line at 4.182 Å and He-like Cl XVI triplet components in the range 4.43 Å-4.45 Å are identified.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Results of detailed investigations of the whole variety of solar activity events are widely used in studies of relevant stellar activity manifestations. On the other hand, investigations of a plenty of active stars which differ in mass and age lead to determination of the decisive factor of the solar activity evolution and give ideas on the past and the future of this activity.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

AE Aquarii is a star with unique flaring activity. It is a close binary system, which contains a K3V-K5V red dwarf (secondary) and a magnetized white dwarf rotating with the period of 33 s (primary). It is traditionally classified as a peculiar nova-like star and assigned to the DQ Her subclass of magnetic Cataclysmic Variables (CVs).To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

From long-term multicolour photometric observations of strongly spotted stars, one concludes usually on a presence of active longitudes. We argue the latitudinal effects in distribution spots over the surface and noticeable equatorward drift of the low-latitude boundary of the spotted region during the rising phase of activity.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The results of photometric investigations of the eclipsing binary CM Dra are presented. The observations of CM Dra were taken with the 70-cm telescope and two-star photometer of the Ural State University Astronomical Observatory in 1996–1997 (the total duration was 155 hours). The solution of the composite lightcurve yielded some fundamental physical parameters of CM Dra components. Four flares were observed, the calculated flare rate was 0.026. The Flares power was about handred times larger than solar ones. The CM Dra composite lightcurve shows the outside-eclipse low-amplitude (0.024mag) brightness variations which appeared to be shifted by 120 degrees in phase over a 20-years period. It may be explained supposing an appearance of the star spots on another longitude.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html