THE PROBLEM OF ACCURATE ORIENTATION OF THE MOBILE TELESCOPE MOUNTS FOR AN AMATEUR ASTRONOMER TO THE DIRECTION ¾TO NORTH POINT¿ IN CONDITIONS OF UNVISABILITY OF THE CELESTIAL POLE AND ITS SOLUTION USING EARTH’S MAGNETIC FIELD

The actual problem of accurately determining the direction to the north point in conditions of the
unvisability of the Celestial Pole is considered in present paper. Its solution is fundamentally necessary
for the correct operation of mobile mounts of amateur-level telescopes without automatic guiding. The
brief overview of the main concepts of spherical astronomy and properties of the modern magnetic
field of the Earth is represented here to solve this problem. Two alternative methods are presented for
calculating the correction A to determine the azimuth of the North point using a magnetic compass:
using the vector method and spherical geometry tools. A comparative analysis of the advantages and
disadvantages of the above methods has been performed. A numerical analysis of the obtained results
was performed. 2D and 3D graphs of the dependencies of the studied quantities are presented. It is
shown that in most of space of the possible values of geographical coordinates the correction module
|A| is a smoothly varying function and takes values O(10◦÷20◦). In the vicinity of the meridians of the
geomagnetic poles, between geographical and geomagnetic poles, sharp changes in the correction value
are observed with a difference of 360◦. The values of A correction were calculated for 16 million-plus
cities in the Russian Federation. It is shown that the correction values are significant and must be taken
into account for the correct orientation in space of an amateur-level telescope mount using a compass
in astronomical observations.