The Fraunhofer spectra were used to study the physical condition variations in the photospheric layers in the course of a bright solar flare. The observations involve both the impulsive and main phases of the flare. The spectral lines are formed in the photosphere at the interval 12–500 km. The modelling was made by fitting the observed and calculated line profiles using the SIR program. The models represent the distributions of temperature, gas density, line-of-sight velocities, etc. on the height. They show some inhomogeneities of these physical parameters at various photospheric levels. Their significant deviations from the VAL-F model may be seen in the course of the flare. The largest heating of the high and middle photospheric levels take place close to two X-ray maxima. At the final flare stage the photosphere is disturbed appreciably while the spectral data testify to the flaring process fading in the chromosphere. This may be an evidence of a disturbance propagation from the upper atmospheric levels to the low ones in the impulsive and main phases.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We report on a novel investigation of the complex magnetism of the quiet Sun which is based on a realistic three-dimensional modeling of the Hanle effect.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

On the base of the interferometric observations during the total solar eclipse on 11 August 1999 magnetic field strength in a coronal volume at the height of 10$^5$ km above the solar limb has been evaluated using an indirect method. A cold coronal emission (CCE), seen in the lines of $H_{\alpha}$ and K CaII, existed there. The conclusion is made that the magnetic field strength in this bulk, before the investigated CCE-region formed, was about 100-200 G.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

In Eselevich V. and M. Solar Phys. 195, 319, 2000 is shown that in brightness rays of the streamer belt from time to time there exist additional plasma streams of enhanced density moves antisunward and occupies a separate ray. The duration of additional streams can range from a few hours to several days. For that reason, some of them may be categorized as sporadic SW streams and the others as quasi-stationary SW streams. Preliminary investigations showed that the leading edge of such streams can be extremely small in width. The purpose of this paper is to verify the conclusions about the existence of additional plasma streams with steep fronts in streamer belt rays, based on analyzing the calibrated data from LASCO/SOHO C2 and C3.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The spectra of the MnI 539.47 nm spectral line were observed in three different sunspots of the NOAA 0431 active region. Perpendicularly to the dispersion axis, the spectra were divided into several strips that covers the quiet photosphere, penumbra and the umbra of the appropriate sunspot. The manganese spectral line parameters variation along the spectrograph slit were determined and analyzed.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The data from the Greenwich Observatory for 1879–2003 (cycles 12–23) have been used to plot a time (Carrington rotations) vs. Carrington longitude diagram of distribution of the rotation–summed daily areas for each sunspot group. It has been revealed that most of the sunspots appear as clusters having common sources (Sunspot Formation Zones) that lie on a surface rotating with a period close to the Carrington rotation period $T=27.2753$ days. At the same time both the active longitudes and medium-size spots shift in the Carrington heliolongitude and rotate at an angular velocity corresponding to the rotation period $T\sim26.8-26.9$ days. An attempt is made to explain contradictory data on the character of rotation of sunspots and active longitudes.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

During the 25 years that the author has been involved in astrometry, the quality of ground-based parallaxes has increased by about a factor of 10 (from 3 mas to 0.3 mas), but the quantity has increased by only a few hundred. When asked, the average astronomer will cite the $H^2$ space missions (Hubble and Hipparcos) as the great advances in astrometry even thought the ground-based work has played a critical role in the understanding classes of stars such as the L- and T-dwarfs. The next decade promises stunning advances in both the quality and quantity of parallax measurements, and both ground- and space-based projects will play significant roles. The Gaia space mission and the various ground-based telescopes with large etendue (DMT, LSST, Pan-STARRS, etc.) will improve the quality or quantity (or both) by factors of a thousand or more. The situation will be discussed, and the author will express his hope that he might live long enough to see the fruits of these labors.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We analyze some of the tens of active regions (AR) each supposed to produce at least one solar flare detected in Gamma- and hard X–rays by the SONG–M spectrometer on board the CORONAS–F satellite. Of special interest is the AR NOAA 9601, which gave rise to the solar flare at 14:30 UT on September 5, 2001 with up to 4 MeV intensity in Gamma and of M6.0 class only in soft X–rays. We examine 1D radio scans of NOAA 9601, taken with the RATAN–600 in Stokes I and V at a set of wavelengths from 1.92 to 10 cm and radio maps taken with the Solar Siberian Radio Telescope (SSRT) at 5.2 cm. The type of this microwave source is classified among the other sources. The some prediction evidences of such type sources are listed.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Polarization of radio emission on the solar disk was studied according to of Nobeyama radio heliograph observations during 1992-2003. The latitude-time diagrams of polarization circular radio emission were constructed. For a decrease of the noises we used several solar images for a day. We found polarization drifts of radio emission in the high-latitudes activity and at latitude band of the sunspots. Process of the magnetic field reversal of the large-scale magnetic field in polarization of radio emission of the Sun was found during 22-23 cycles. An analysis of polarization for the structures various brightness temperatures has been carried.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

After a careful study of Mars observations obtained by Tycho Brahé (1546-1601), Kepler (1571-1630) discovered the now-called Kepler's third law. In 1627 he published his famous Tabulae Rudolphinae, a homage to his protector Rudolph II (1552-1612), tables (Kepler 1609, 1627) from which he predicted Mercury and Venus transits over the Sun. In 1629 Kepler published his Admonitio ad Astronomos… Advertisement to Astronomers (Kepler 1630), Avertissement aux Astronomes in French Au sujet de phénomènes rares et étonnants de l'an 1631: l'incursion de Vénus et de Mercure sur le Soleil. This was the beginning of the interest of French astronomers, among many others, in such transits, mostly for Venus, the subject of this paper in which dates are given in the Gregorian calendar.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

A major goal in solar physics has during the last five decades been to find how energy flux generated in the solar convection zone is transported and dissipated in the outer solar layers. Progress in this field has been slow and painstaking. However, advances in computer hardware and numerical methods, vastly increased observational capababilities and growing physical insight seem finally to be leading towards understanding. Here we present exploratory numerical MHD models that span the entire solar atmosphere from the upper convection zone to the lower corona. These models include non-grey, non-lte radiative transport in the photosphere and chromosphere, optically thin radiative losses as well as magnetic field-aligned heat conduction in the transition region and corona.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

The paper is devoted to the coronal bright points. We carried out the analysis of the simultaneous observations in IR He $\lambda$10830 Å and microwaves at 5.2 and 1.76 cm. It was obtained that microwave sources correspond to the dark points in IR He $\lambda$10830 Å with line-of-sight velocities directed from a observer. The possible mechanism of the energy transport within the bright points are suggested.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The comparison of the polarization presence in Ellerman bombs or moustaches and the active region arch structure was carried out. In the most cases of the polarization, interpreted as impact polarization, were detected in that regions where the bright small loops were observed. On the contrary, when a significant polarization wasn't detected the scanning during observation was carried out nearby the large loops.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

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

There are dozen instruments successfully operating aboard the solar satellite CORONAS-F, which was launched in the summer of 2001. Among them are two (Polish-led) Bragg crystal spectrometers – RESIK and Diogeness – recording solar flare and active region spectra. A short description of the CORONAS-F satellite operation is presented together with that of the two Polish spectrometers, stressing their unique characteristics. The average spectra have been derived and shown here, covering the wavelength range between 3 Å and 7 Å. Future steps in the analysis of the large database collected are outlined.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Multi-wavelength imaging of the solar corona is a powerful observational method to study CME-related dynamics of structures in spectral bands related to the solar corona and transition region. We analyze large-scale eruptive events caused by halo-type CMEs observed at the solar disk with the CORONAS-F/SPIRIT (175, 304, and 284 Å) and SOHO/EIT telescopes on November 4, 2001 and October–November, 2003. For most events, CME-associated dimmings coincide in different bands, but the 304 Å dimming in November 4, 2001 event was delayed by $>1/2$ hours. In October–November events, coronal waves were observed in 195 Å and some in 175 Å channel. In a CME event associated with a filament eruption on November 18, the SPIRIT images display a propagating disturbance seen as a darkening in 304 Å channel only. This phenomenon was not described earlier.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

The average sunspot activity level for the last millennium is reconstructed. There is a good agreement between the reconstructions, independently built by different proxiesThe full version of this paper can be found at http://www.gao.spb.ru/personal/ivanov/papers/mil-iva-iaus2004.pdf.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html