Page:Philosophical Transactions - Volume 095.djvu/281

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253
Motion of the Sun, and solar System.

apparent motion of the six stars, will be much reduced. The quantities which are required for constructing another figure to represent the threefold motions of our six stars, when a different apex is fixed upon, are to be found by the same method we have pursued in the instance of λ Herculis; and the figure that has been given with respect to that star, shows evidently that the parallactic line S P should, be turned more towards the line s a, representing the apparent motion of Sirius. We shall accordingly try a point near the following knee of Hercules, whose right ascension is 270° 15', and north polar distance 54° 45'.

The result of a calculation of the angles and the least quantities of real motion of our six stars, according to this apex, is collected in the following Table, and represented in Fig. 3.

Table VI.

Stars.

Angles of the parallactic Motion
with the Parallel.

Angles of the apparent with the
parallactic Motion

Least Quantities
of the
real Motion.

° ' " ° ' " "
Sirius 68 51 5 south-preceding 0 1 25 south preceding 0,0004561
Arcturus 29 30 32 south-preceding 25 59 10 south-following 0,9145072
Capella 77 54 0 south-following 6 18 38 south-following 0,0509727
Lyra 27 38 47 north-following 28 42 9 north-preceding 0,1557761
Aldebaran 66 20 17 south-following 10 9 21 south preceding 0,0217607
Procyon 64 48 27 south-following 14 46 1 south-preceding 0,3159051
Sum 1",4593779

By this Table it appears that the annual proper motion of our six stars may be reduced to 1",4594, which is 0",7655 less than the sum in the 5th Table, where the apex was λ Herculis.

In the approximation to this point it appeared, that when the line of the parallactic motion of Sirius is made to coincide