Search Publications
Formation of Sources for Solar Cosmic Rays in Eruptive Flares X6.9 and M5.1 Observed August 9, 2011, and May 17, 2012
Struminsky, A. B.; Grigorieva, I. Yu.
A coronal mass ejection (CME) and solar proton event (SPE) succeeding weak flares in soft X-rays and being observed in the interplanetary space (IS) is not any unusual. However, it remains unclear in what way extreme CME and SPE characteristics can be realized in such cases. The present work compares solar and IS observations associated with the l…
Study of the Magnetic Properties of Sunspot Umbrae
Obridko, V. N.; Fainshtein, V. G.; Rudenko, G. V. +1 more
The paper presents the results of the study of sunspots, obtained by the authors and other researchers in recent years. The results regarding the atmosphere above sunspot umbrae, based on the observational data in the spectral lines of the upper chromosphere and lower corona, are discussed. It is shown that individual parameters of the profile of …
Solar Photospheric Magnetic Fields, Coronal Mass Ejections, and Type II Radio Bursts in Cycles 23 and 24
Bilenko, I. A.
We consider the events of type II radio bursts (RBII) in the decametric and hectometric ranges from 1 to 16 MHz and the dependence of the parameters of associated coronal mass ejections (CMEs) on the background characteristics of the plasma and interplanetary magnetic field (IMF) in the regions where each radio burst was detected in solar cycles 2…
Analysis of Study Results of the Polar Coronal Hole on the Sun According to Observations in the Microwave Wavelength Range
Golubchina, O. A.
An overview is presented of the main results of the study of the polar coronal hole over the North pole of the Sun based on observations of the solar eclipse on March 29, 2006, using the RATAN-600 radio telescope in a wide cm-range of wavelengths (1.03, 1.38, 2.7, 6.2, 13.0, 30.7 cm) along with observational and theoretical data about the properti…
Evolution of solar active regions: Detecting the emergence of new magnetic field through multifractal segmentation
Golovko, A. A.; Salakhutdinova, I. I.
New emerging magnetic flux is identifed using a multifractal segmentation method used to investigate regularities in the evolution of active regions and activity complexes. The SOLIS, MDI SOHO, and SOT Hinode magnetograms were used. Observations of the active region NOAA 10488 on October 26-28, 2003 indicate considerable variability of areas of ne…
Active regions near the recent solar-cycle minimum: Relation between plasma heating and electrical currents
Livshits, M. A.; Rudenko, G. V.; Grigor'eva, I. Yu. +1 more
Data on small active regions on the Sun collected over three years (2007-2009) are analyzed. Under very quiescent conditions (a low X-ray background level), the shapes of the coronal loops of some active regions correspond fairly well to the shapes of magnetic-field lines calculated in a potential approximation. This is true of several active regi…
Low-energy 3He and 4He ions in interplanetary space during quiet periods of the 23rd solar cycle
Kecskeméty, K.; Logachev, Yu. I.; Surova, G. M. +1 more
Data from the ULEIS instrument aboard the ACE spacecraft are used to study the energy spectra of 3He and 4He ions produced during periods of the quiet Sun in the 23rd solar cycle in the energy range ∼0.08-2 MeV/nucleon. Differences in the spectra and 3He/4He relative abundances for three groups of quiet …
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
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…
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 …