Structure and Development of Solar Active Regions

Welcome by the Hungarian Academy of Sciences.- Preface and introduction.- I General Development of an Active Region.- Patterns of active region magnetic field development.- Origine des régions actives solaires ‘anormales’.- Magnetic classification of active regions.- Development of magnetic fields in active regions.- The balance of magnetic fluxes in active regions.- On the birth of some proton-flare regions.- Some patterns in the development of centers of solar activity, 1962-66.- Last phases of development of active regions.- On some properties of the velocity field in a developed active region.- The migration of sunspot activity along solar meridians and parallels.- Chromospheric explosions and satellite sunspots.- Study of an active region of the Sun during three rotation periods.- II Theoretical Aspects.- Magnetohydrodynamics of an active region.- Concentration of magnetic fields in the deep convection zone.- Oscillatory modes of energy transport in solar magnetic regions.- On the magnetic structure of an active region.- Oscillatory convection in strong magnetic fields and origin of active regions.- Quantitative estimations of the anomalous plasma diffusion in an active region.- Étude critique d’un champ ‘current-free’ dans l’atmosphère solaire.- Sunspots and magnetohydrodynamic flows.- III Optical Structure of an Active Region.- On the state of the photosphere before the appearance of sunspots.- Correlations between brightness fields and magnetic fields on the Sun.- The supergranular pattern and the stable stages of sunspot groups.- The intensity, velocity and magnetic structure in and around a sunspot.- Fine structure of brightness, velocity and magnetic field in the penumbra.- Concerning the development of the Evershed motion in sunspots.- The connection of fine-structure photospheric features in active regions with magnetic fields.- On the magnetic-field configuration in sunspots.- The proper motions of sunspots and the magnetic field of active regions.- Fluctuations of the magnetic-field strength of sunspots within one day.- On the structure of the magnetic field of sunspots.- Magnetic and Doppler oscillations in active regions.- Preliminary communication on the short-period oscillations of solar magnetic fields.- Some comments about correlations between magnetic field and velocity, magnetic field and line intensity in the undisturbed photosphere.- On some spectrographic observations related to the structure with height of active regions and particularly solar flares.- Chromospheric heights in active regions.- The structure of the lower solar chromosphere in undisturbed and active regions.- Problems in the interpretation of polarization measurements in active regions.- On the magnetic-field structure around filaments.- The formation, structure and changes in filaments in active regions.- Prominences in active regions.- The ‘detwisted’ prominence of September 12, 1966.- Loop-prominence systems and proton-flare active regions.- Bright points (moustaches) and arch filaments in young active regions.- Solar active regions in Mg II light.- IV Cooperative Study of Solar Active Regions (CSSAR).- Introductory report.- Flare activity and spotgroup development.- A study of the localization of flares in selected active regions.- Evolution of Ca plages of the CSSAR active regions.- Correlation between Ca plages and longitudinal magnetic fields of the CSSAR active regions.- Évolution des émissions coronales au cours de la vie d’un centre actif.- V Coronal and Interplanetary Structure of an Active Region.- Observation des jets et concentrations d e la couronne au-dessus des régions actives.- Influence of magnetic fields on the structure of the solar corona.- Photographs of coronal streamers from a rocket on May 9, 1967.- New aspects of the role of development and structure of solar active regions in the arrangements of the corona based on its geomagnetic displays.- Active regions and the interplanetary magnetic field.- Extreme ultraviolet observations of active regions in the solar corona.- Protons associated with centres of solar activity and their propagation in interplanetary magnetic-field regions co-rotating with the Sun.- The solar corona above active regions: a comparison of extreme ultraviolet line emission with radio emission.- On some aspects of XUV spectroheliograms.- La composante lentement variable des rayons X solaires en relation avec la structure des centres d’activité.- X-radiation studies of the corona.- Observations of energetic X-rays from quiescent solar active regions.- X-ray picture of the Sun taken with Fresnel zone plates.- The significance of the polarization of solar short- wavelength X-rays.- VI Transient Phenomena.- Analysis of some solar flares from optical. X-ray, and radio observations.- Interaction of magnetic fields and the origin of proton flares.- A model of solar flares.- The high-energy flare plasma.- The occurrence and possible meaning of the ‘nimbus’.- Flare-produced coronal waves.- The observation of 10-50 KeV solar flare X-rays by the OGO satellites and their correlation with solar radio and energetic particle emission.- VII Proton Flare Project (PFP).- and summary.- Observations of the solar proton event of August 28, 1966.- Sunspot changes following proton flares.- VIII Radio Structure of an Active Region.- Homology of solar radio events.- Some results on solar activity at 408 MHz.- Conditions of acceleration of solar electrons, and determination of the magnetic field in the high corona from the characteristics of a type-IV burst.- Tendencies to repeating of type-IVm bursts and their relations to the stage of development of the sunspot group.- Properties of sources of the slowly varying component of 2 cm solar radio emission.- Some properties of the sources of slowly varying and component and of bursts at 612 Mc/s.- Satellite observations of solar radio bursts.- Comparison of 8-mm solar radio features with local magnetic fields and chromospheric features.- Radio emission of spotgroups.- Quelques relations entre sursauts radioélectriques solaires sur ondes décimétriques et caractères mor-phologiques des éruptions chromosphériques associées.- The effect of compression and expansion of plasma on the generation of synchrotron radiation.- The great burst of May 23, 1967.- Summarizing Review.- The development and structure of an active region.