On the systems of selenographic coordinates,their determination and terminology

Attention is drawn to the absence in literature of the precise definitions of selenographic and celestial selenocentric coordinate systems. In certain cases inaccuracies in the formulation of the first Cassini law occur. This is due to the fact that the principal directions dealt with in the theory of lunar rotation are being constantly confused. A clear-cut definition of the principal coordinate systems concerned with the lunar rotation is given. It is indicated that there is no necessity in a special astronomical time service on the Moon. Since the future expeditions to the Moon will be able to keep terrestrial time, the problem of the hour angle is simply solved by the Formula (11).     

On the origin of ancient lunar magnetic fields

The maximum value of possible lunar dynamo-field in our epoch is estimated in the scheme of precession dynamo model. In the light of our notions on the evolution of the Earth-Moon system this scheme may account for the size and character of ancient lunar fields that resulted in magnetization of surface lunar rocks, as well as for the absence of lunar dipole field of paleomagnetic origin in our epoch.     

Radial velocities of the components of multiple star systems of Trapezium type. I

Translated fromAstrofizika, Vol. 36, No. 2, pp. 273–275, April–June 1993.     

Relative deformations of selenodetic nets of coordinates

One of the main problems of selenodesy consists of the construction of a net of basic reference points on the surface of the Moon. At present there exist many catalogues containing the coordinates of selected objects on the Moon. These catalogues differ by the presence of both systematic and accidental errors.The investigations concerning the comparison of catalogues and the elucidation of their systematic differences are of very recent date. Various methods of interpretation of the systematic differences between catalogues have been proposed. Without an attempt to encompass the whole problem in what follows, we shall describe one method for comparative study of catalogues based on the theory of the deformation of continuous media.