Dr. Oscar Stumpe, of Berlin, made a list of 996 stars having proper motions between 16″ and 128″ per century. He divided them into three groups, the first including those between 16″ and 32″; the second between 32″ and 64″; the third between 64″ and 128″. The number of stars in each group and the position of the apex derived from them are as follows:
| Gr. | I, | 551 stars; A = | 287°.4; | D = × 45°.0 |
| II, | 339 | 282°.2 | 43°.5 | |
| III, | 106 | 280°.2 | 33°.5 |
Porter, of Cincinnati, made a determination from a yet larger list of stars with results of the same general character.
These determinations have the advantage that the stars are scattered over the entire heavens, the southern as well as the northern ones. The difference of more than 10° between the position derived from stars with the largest proper motions, and from the other stars, is remarkable.
The present writer, in a determination of the precessional motion, incidentally determined the solar motion from 2,527 stars contained in Bradley’s Catalogue which had small proper motions, and from about 600 more having larger proper motions. Of the latter the declinations only were used. The results were:
| From small motions: | A = 274°.2; | D = × 31°.2 |
| From large motions: | 276°.9 | 31°.4 |
From all these results it would seem that the most likely apex of the solar motion is toward the point in
| Right Ascension, | 280° |
| Declination, | 38° north. |
This point is situated in the constellation Lyra, about 2° from the first magnitude star Vega. The uncertainty of the result is more than this difference, four or five degrees at least. We may therefore state the conclusion in this form:
The apex of the solar motion is in the general direction of the constellation Lyra, and probably very near the star Vega, the brightest of that constellation.