[en] These volum proceedings on plasma astrophysics contain 63 contributions which are all in INIS scope. They are subdiveded intot the following categories: results of space projects, solar wind and planetary magnetospheres, sun and normal stars, interstellar medium and schock waves, reconnection of magnetic fields in space and dynamos, acceleration mechanisms and cosmic rays, accretion, disks compact objects and active galaxies, galactic structure dynamics and cosmology, and laboratory plasma physics. (author). refs.; tabs

[en] An interest in maagnetic reconnection on the Sun was first stimulated by solar flare observations, which require fast quasi-steady reconnection to explain the observed energy release. Reconnection is now thought to play several roles in flares, including the creation of small events, the triggering of large events and the formation of rising flare loops. Also, it is important in many other solar phenomena such as coronal heating, coronal mass ejections, prominences, magnetoconvection, dynamo generation and cancelling magnetic features in the photosphere. There have recently been many advances in basic theory and its application to particular reconnecting situations. 2D steady reconnection may operate in many different regimes, such as slow mode compression, hybrid or flux pile-up, depending on the imposed boundary conditions. For example, Biskamp's numerical experiment gives a good example of flux pile-up. If reconnection develops locally from an instability and the boundary conditions are free, then Petschek's regime of fastmode expansion is produced, but if reconnection is driven from outside by, for example, an ideal instability, then flux pile-up is more likely. Furthermore, numerical experiments are shedding new light on the global eruptive instability of coronal arcades and the way reconnection occurs as prominences erupt. For a 3D magnetic field such as exists above sunspots or magnetic fragments of complex polarity or in prominence fields, it is suggested that reconnection may be defined to occur when there is a singular line (a field line with neighbouring X-type topology and an electric field along it). In general there is a continuum of potential singular lines an which one supports reconnection depends on the flow or electric field. An example is given of how to drive reconnection all along any curved field line in a configuration with shear and it is found that strong plasma jetting occurs along the singular line. Thus in a sheared coronal configuration of potential singular lines, coronal heating may occur at small current sheets created at singular lines by the appropriate flows. (author). 58 refs.; 14 figs

[en] An experimental study is made of the evolution of a magnetic type-X structure which is produced on a theta-pinch device. It is found that during the initial stage the reconnection process is proceeding in a spontaneous fashion, with periodic restructurings of the current sheet and abrupt accelerations of ions. In the subsequent stage it is stationary in character, with the reconnection rate being in agreement with estimates obtained in terms of the forced reconnection Sweet-Parker model. (author). 11 refs.; 6 figs

[en] Applying the model of Molodensky et al. we have investigated the fibril directions (H-alpha level) for the penumbran and superpenumbran region of a sunspot, namely the main, but following spot of the small, simple active region SD 135/1984 on June 24. To reduce the number of free parameters of the model we used vector magnetograms. Comparing structures of H-alpha filtergrams and heliograms with the theoretical field model we got the following information: The chromospheric structure of the sunspot magnetic field was essentially a result of two subsstems. The two sources had nearly the same magnetic flux densities, a very small distance relative to the sunspot areal, and the resulting magnetic field topolog had nearly a current-free configuration. These results are in good agreement with earlier investigations of this active region. (author). 7 refs

[en] In recent years observations of OB and Wolf-Rayet stars have shown them to be unexpectedly strong sorces of X-ray and radio radiation. Non-thermal radio emission shows the presence of relativistic electrons and magnetic fields far out in the powerful stellar winds that are characteristic of these stars. This suggests an alternative interpretation of the X-ray emission to Lucy and White's shock model as a result of the rapid Compton cooling that energetic electrons would suffer against photospheric radiation. It is proposed that it is the ubiquotous presence of relativistic electrons in early-type stellar winds that is the cause of both radio and X-ray emission and that magnetic reconnection in single and colliding pairs of winds may be the agent of the electron acceleration. (author). 13 refs. agent of the electron acceleration. (author). 13 refs

[en] Solar photoelectric magnetographs measure the state of polarization in magnetosensitive spectrum lines. The derivation of magnetic field parameters from such data requires a 'calibration' in terms of a transfer theory for polarized radiation, therefore it depends on model assumptions. The primary polarimetric measurements are influenced by disturbances introduced within the telescope and in the atmosphere of the Earth. We review the basic uncertainties encountered in the interpretation of magnetograph data, but also possibilities for deriving more reliable information. The problems are illustrated by describing the data handling of the Potsdam vector magnetograph in more detail, moreover, examples of observed flare- active regions demonstrate the state of information which nowadays can be obtained. (author). 21 refs.; 3 figs

[en] The evolutionary coincidence between the occurrence of the LDE flares and the formation of the evolving delta configuration, in the certain active region, was found. 51 cases of LDE flares have been analysed from the viewpoint of the precise location of their flare loop arcade (located above delta configuration). The quasi delta configurations (i.e. kinematical joining of the two stable spots of the opposite magnetic induction) are not LDE flare productive. (author). 27 refs.; 2 tabs

[en] We discuss our present understanding of magnetotail reconnection leading to plasmoid formation and ejection. We emphasize three-dimensional structures and deviations form earlier imposed symmetries, based on MHD simulations and topological considerations. We find that, in general, the separation of the plasmoid will take a finite amount of time. During this stage the plasmoid is characterized by filamentary structures of interwoven flux tubes with different topological connections. (author). 12 refs.; 7 figs

[en] A quasiperpendicular shock is considered as a structure, evolved from a fast magnetosonic nonlinear wave. Due to the steepening and tendency towards overturning the scales become smaller and the ramp is an intermediate whistler. The noncoplanar magnetic field component in the ramp appears in a quite natural way. The ramp is characterized by a large peak of the potential electric field, its width is much smaller than the ramp width. It is shown that in such a case electrons are heated efficiently. Ions are heated also, the heating process is closely related to the shock drift acceleration. (author). 8 refs.; 6 figs

[en] Small-scale hydrodynamic instabilities - the shear instability and thermal convections, which can provide turbulization of accretion disks of compact objects have been analysed. Actually domains of the existence of each of these instabilities are determined; it is shown that shear turbulence has no gyrotropic nature, while the thermal convection has and can generate a large-scale magnetic field; sequences of the difference in statistic characteristics of these turbulences are described depending on the extensions of the domains of their existence. (author). 16 refs.; 2 figs