The technological choices selected for the need of the International Research on the Interior of the Sun (IRIS) network are examined. Special attention is given principles of electronic measurements by the IRIS instrument, the instrument's critical components and specific requirements, and calculations of theoretical sensitivity of the IRIS

A general panorama of SS Cygni is presented. The paper first describes the CV cataclysmic variables and the current theories which attempt to describe their physical behavior. The up-to-data observational properties of SS Cygni are examined together with an explanation of their nature within the framework of existing theories.

The question of which estimator of the two-point correlation function has the smallest sampling error is discussed. An expression is given for this smallest sampling error in terms of the correlation functions, although it is found to be of rather limited use. A more useful approach is considered, in which the sampling error is shown to be made up

The propagation of interstellar jets is examined by means of numerical modeling. The jets result from the injection of an overpressured supersonic beam of gas into the interstellar medium, and have been followed time dependently up to distances of 0.2 pc from their injection point while preserving a high degree of collimation. As the jets propagate

CCD maps are presented of the inner 1.4 kpc of NGC 4736 in the B, V, R, I and Z bands, along with an ellipticity analysis of these, in which the ellipticities and position angles of isophotal best-fit ellipses are given as functions of galactocentric radius in each band. Also provided are calibrated profiles through the nucleus in individual bands

The discovery is reported of a new lithium super-rich carbon star, IY Hya, and the Li abundance in three other carbon stars (T Sgr, WZ Cas and WX Cyg), previously known as super Li-rich stars is derived. All these stars show abundances in the range log N(Li) = 4.5 (i.e., 10 to 100 times higher than the present cosmic value). Two of them (WX Cyg and