A note on the magnetic network of photospheric magnetic fields

It is suggested that the magnetic network in the unipolar region of the photosphere can be interpreted as the field of loop currents along the boundary of the supergranulation cells. The currents are generated by the dynamo process associated with the supergranulation.     

A note on the stability of helical velocity and magnetic fields

The stability of nonparallel helical velocity and magnetic fields in a plasma cylinder with free boundaries is examined. It is shown that, in case of weak helicity, the stability of the system remains unaffected.     

A note on magnetic fields and electric currents in solar prominences

We determine magnetic fields and electric currents in three prominences without simplifications used in our previous papers.     

Force-free magnetic fields in static media

In a static resistive medium, a force-free magnetic field must decay exponentially with time while preserving the form of its field lines. This has been proven by Jette (1970) in an extremely complex way. In the present paper a simpler proof of the same result is given.     

A note on some unusual velocity values of the Be star o And

Die Radialgeschwindigkeiten für die Ca II (K)-, Na (D)- und Balmer-Linien wurden für den Be Stern o And bestimmt. Die zeitlichen Variationen der Geschwindigkeiten, besonders die der Ca II (K)-Linie, können durch die Existenz eines Begleiters erklärt werden.     

Comment on ‘note on the stability of parallel magnetic fields’

It is shown that the conclusions arrived at regarding the instability of an incompressible fluid cylinder in the presence of the magnetic field and the streaming velocity in a recent communication easily follow from the study of propagation characteristics of Alfvén surface waves along cylindrical plasma columns made earlier.     

A note on variable-G cosmologies

An example of a cosmological model with variable gravitational couplingG and a time-dependent cosmological term , has recently been presented. It has been shown that there is no creation of matter and that the rest mass of particles stays constant in this model. In this paper we will generalize the field equations to the case where bothG and depend both on time and position. It is shown that even in this case there may be no creation.     

A note on antimatter meteors

It is argued here that unless antimatter meteors can be shown to possess some unambiguously unique characteristic not displayed by ordinary koinomatter meteors, it will be difficult to infer their existence given the standard interpretation of meteoroid structure. It is also argued, however, that the existence of antimatter meteors is extremely unlikely.     

A note on weak stability boundaries

This paper is devoted to clarify the algorithmic definition of the weak stability boundary in the framework of the planar Restricted Three Body Problem. The role of the invariant hyperbolic manifolds associated to the central manifolds of the libration points L ₁ and L ₂, as boundary of the weak stability region, is shown.     

A note on the averaging method

When time-averaged equations are used to discuss the secular behavior of dynamical systems, the action-angle variables conjugate to the action variables of the unperturbed motion of the system should be chosen as dependent variables; otherwise, the results are not correct.Presented at the Division of Dynamical Astronomy Meeting of the American Astronoming Society, Chapel Hill, N.C., U.S.A., December 4, 1976.     

A note on critically rotating polytropes

The structure of critically rotating polytropes is calculated using two (reated) Roche-type approximation schemes, one of which has been developed for stellar models. Comparisons with other results are made as a validation of these methods in stellar structure calculations.     

A note on vacuum self-creation cosmological models

The vacuum field equations of the self-creation theory of gravitation are solved for the Robertson-Walker space-time, by using a correspondence to known solutions of general relativity.     

A second note on Hori-Lie perturbation technique

In this second note we show how to avoid the introduction of Hori's pseudo-time in analytical planetary theory in the case of the eight principal planets of our solar system excluding Pluto.     

A note on the BBSAG visual observations

This Letter contains some comments on the communication by Diethelm and Locher (1988) concerning the period variations in the eclipsing binary systems EE Aqr, BZ Eri, IZ Per, and VZ Hya. Significance of the BBSAG visual observations has been discussed.     

A note on the linear stellar model

For a purely gaseous self-gravitating stellar configuration with linear matter density distribution the total power generated by nuclear reactions is considered. The analytic connection between physical parameters of the macroscopic and microscopic levels of the stellar equilibrium configuration is revealed.     

A note on computer-aided planetary remote sensing

An example is presented to assist remote sensing scientists in their orientation towards the digital analysis of planetary image data.     

A note on the Hori-Lie perturbation technique

In this paper we describe how to avoid the introduction of Hori's pseudo time in general planetary theory in the case of two planets.     

Singularity-free static centrally symmetric solutions of some fourth order gravitational field equations

The fourth order field equations proposed by TREDER with a linear combination of BACH 's tensor and EINSTEIN 's tensor on the left-hand side admit static centrally symmetric solutions which are analytical and non-flat in some neighborhood of the centre of symmetry.     

A note on vacuum solutions based on Lyra's manifold

In a recent Letter to the Editor, Beesham (1986) has claimed that the models based on the Lyra manifold allow a wider class of solutions of the vacuum field equations than models based on a Riemannian manifold. It was also argued that the cosmological term is introduced in an arbitraryad hoc fashion in general relativity.In this note I will show that all the vacuum solutions found by Beesham, can equally well be solutions of the Friedmann equations of vacuum with a cosmological term. All these solutions are well known.