1. Introduction

[2]  During the last decade the new ground (Mark 3-4) and satellite SOHO/Large Angle and Spectrometric Coronagraph Experiment (LASCO) coronagraphs were realized for regular measurements of electronic density in solar corona. These data essentially expand the long series of coronal observations of the K or white corona using out of eclipse and episodic observations during the eclipses. It was well known that different type of the observations reflects various brightness of the corona. For example, the observations of internal corona in EUV and X-ray ranges (SOHO/EIT-171A) displayed the arch structures of the corona above bipolar active regions at heights of 1.1 R-1.2 R and the regions of diffusion coronal brightness at heights up to 1.1 R [Tlatov and Makarov, 2003]. Diffusion corona was observed also outside of coronal holes above the large-scale magnetic fields of mixed polarity during the minimum of solar activity. Observations of the K or white corona during the eclipses show presence of the structures, having increased electron density in coronal plasma, at heights up to several radiuses of the Sun. This distribution of electron density slightly differs from one in spectral corona. For example, bright K coronal structures exist during an epoch of the minimum activity. The polar K corona was observed too in an epoch of the maximum activity. Such distribution of electron density in the corona connects with presence of heliosphere neutral current layer [Hoeksema, 1984]. It was shown that bright coronal streamers cuddle up to heliosphere neutral current layer at heights more than 2.5 R and they form the belt of coronal streamers [Bohlin, 1970]. The heliosphere current layer was located near solar equator during the solar minimum. It reached the high latitudes of the northern and southern hemispheres with development of solar cycle and it has been folded [Wang and Sheeley, 1992]. The sources of coronal condensation can be connected with the active regions and neutral lines of the large-scale magnetic field that tracer by the filaments and prominences in chromosphere. The large-scale field of the Sun in chromosphere and low corona has a zonal structure that separates the regions of magnetic field of opposite polarity. The neutral lines of magnetic field are displaced to the poles with development of solar cycle and they can be considered as independent belts in different hemispheres of the Sun. In this paper we consider the solar corona at heights of 2.3 R-5.5 R to determine the basic sources of coronal brightness and nonradial direction of the streamers.