Search Publications
Fractal properties of active regions
Golovko, A. A.; Salakhutdinova, I. I.
The dynamics of active regions have been investigated using multi-fractal analysis methods, based on magnetograms of the full solar disk in the 630.2 nm line obtained with the SOLIS vector spectromagnetograph of Kitt Peak Observatory (USA) during 2006-2007 and January 1, 2009-April 12, 2010. The applied method of multi-fractal segmentation reveals…
IR photometry and dust-shell models for two carbon stars
Bogdanov, M. B.; Taranova, O. G.
We present JHKLM photometry of the carbon stars ST And and T Lyn acquired in 2000-2010. Along with brightness variations due to pulsations, changes on timescales of 2000-3000 days are also observed. Our combined light curves can be satisfactorily represented with light elements derived from visual observations, but the maxima are delayed relative …
Relations estimated at shock discontinuities excited by coronal mass ejections
Eselevich, M. V.; Eselevich, V. G.
An analysis of SOHO/LASCO C3 data shows that there are discontinuities in the radial profiles of the plasma density within limited regions in front of each of ten coronal mass ejections, which represent shocks. The shock velocities in various events reach V ≈ 800-2500 km/s. A comparison of the dependence of the AlfvenicMach number M
Analysis of light curves of eclipsing systems with exoplanets: HD 189733
Cherepashchuk, A. M.; Abubekerov, M. K.; Gostev, N. Yu.
High-accuracy multicolor light curves of the binary system HD 189733, which contains an exoplanet, are analyzed. We have determined the radii of the star and the planet in the binary system, as well as the orbital inclination. The limb-darkening coefficients of the stellar disk were obtained in 10 filters in the wavelength interval λλ = 5500-10 50…
Dynamical study of the wide visual binary ADS 12815 (16 Cyg)
Kiselev, A. A.; Romanenko, L. G.
A homogeneous series of photographic position measurments of the visual binary ADS 12815 obtained on the 26-inch refractor of the Pulkovo Observatory (1960-2007) is analyzed. The Pulkovo observations allow for the existence of the planet around component B discovered by Cochran et al. based on radial-velocity measurements. The orbit of the planet …
Some properties of the development of the perturbed zone and shock preceding a coronal mass ejection
Eselevich, M. V.; Eselevich, V. G.
SOHO/LASCO C2 and C3 data have been used to carry out a detailed study of the perturbed zone and shock that form as a coronal mass ejection (CME) moves away from the Sun, as a result of its interaction with the ambient solar wind. The event of January 4, 2002 is used as an example. The perturbed zone is most extensive along the direction of propag…
The inverse problem of the theory of degenerate dwarfs
Vavrukh, M. V.; Smerechynskyi, S. V.; Tyshko, N. L.
Based on the radii and masses of degenerate dwarfs derived from HIPPARCOS and other observations, we estimate the microscopic parameters of a Chandrasekhar model (the relativistic parameter at the stellar center x 0, and the chemical-composition parameter µ e = A/Z, where A is the mass number and Z is the nuclear charge). We…
A tropospheric signal delay model for radio astronomical observations
Molera Calvés, G.; Duev, D. A.; Pogrebenko, S. V.
In this work, a three-dimensional refraction model is proposed, which allows one to calculate the delay of signal due to the Earth's troposphere—the main source of error limiting the accuracy of modern radio astronomical observations. The method of raytracing through the three-dimensional troposphere (numerical weather model) is used. The results …
Magnetic activity of the star Corot-Exo-2a
Savanov, I. S.
Continuous photometric observations of the young active solar-type star Corot-Exo-2a using the “Corot” space telescope obtained over 142 days were used to analyze the star’s surface temperature inhomogeneities and to monitor their continuous evolution. This analysis was based on the iPH code, which reconstructs the distribution of temperature inho…
Detecting the widths of shock fronts preceding coronal mass ejections
Eselevich, M. V.
The perturbed zones and shocks preceding coronal mass ejections (CMEs) are studied using the data of the Mark 4, LASCO C2, and LASCO C3 coronagraphs. Detection of the perturbed zone indicating the presence or absence of the shock is most reliable in a frame moving with the frontal structure of the CME. The ability to correctly measure the width δ …