| Abstract: | The principle of the maximum set of stars without proper motions (μ = 0) requires that the corrections of the precession be specified so that the number of the stars “without proper motion” (practically μ < 0″.10) becomes a maximum. These stars are named the “Träger” (carriers) of the non-rotating coordinate system. The method avoids any hypothesis about the distribution of the proper motions and hence does not use the method of least squares. The procedure algorithmized in the FORTRAN language and computed on a UNIVAC 1108 is based on the geometric means of a regular sequence of numbers of stars within concentric circles around the position μ = 0 with growing radius in a rightangle coordinate system with the axes μαcos δ and μδ. The main concept is the “zero-point density” D in the defining equation (13). The inequality (15) is the main relation of the method, where r is the radius of a circle-neighbourhood of the position μ = 0. The main part of the procedure in praxi and the algorithm are described in section 5. In sections 6, 7 and 8 the method is applied to the proper motions of the catalogue FK4, then to the proper motions of the catalogue N30 and finally to a third catalogue, which consists of the proper motions of N30 reduced to the system of FK4 (N30 → FK4). The main result lies in table 4 of section 9. With regard to the accuracy as well as to the number of the “Träger” (carriers) of the coordinate system free of rotation the results from (N30 → FK4) have the following implications: the corrections of lunisolar precession Δp1 = +0″.97 ± 0″.04 per century; the correction of the motion of equinox Δp2 = Δλ + Δc = +1″.10 ± 0″.04 per century. For the motion of equinox Δp2 = Δλ + Δc = +1″.10 ± 0″.04 per century. For the purpose of investigations of motions of stars these corrections correspond to the corrections (21) of the proper motions of N30 → FK4. The new method has the advantage also, that fewer than half of the stars of a catalogue can influence the result (table 6). |
