Weekly expositor. (Brockway Centre, Mich.) 1882-1894, 1889-01-10
ACCOMMODATED Facts.

The Uranometria Nova, Of Arge-
landa, gave the positions OF the lucid
stars of tho northern sky, and it has
been supplemented by the Uranome.
tria Argentina of DIR. Gould, which
covers the southern sky. With the
stellar statistics of the whole sky be-
fore him, DR.. Gould was in position
TO draw some extremely interesting
conclusions with respect TO the arrange
ment of the brighter stars in space, and
to the situation of our solar system in
relation to them. The outline of his
reasoning is given by a writer in Scrib-
ner's. In the first place il is fairly
proved that in general the stars that
are visible to the naked eye (the lucid
stars) are distributed at approximately
equal distances one from another and
that, on the average, they are OF APP
proXimately equal brilliancy. If we
make table of the number Of stars of
each separate magnitude in the whole
sky we shall find that there are proper
tiOnately many more OF the brighter
ones (from first TO fourth magni-
tudes) than of the fainter Crom fourth
TO seventh magnitudes). That is, there
is an unfailing and Unsystematic excess
of the observed number of the brighter
stars" We cannot suppose, taking one
star with another that the difference
between their apparent brightness
arises simply from real difference IN
size, but we must conclude that the
stars from the first to fourth magnitudes
(some 300 are really nearer to us than
the fainter stars. 1t therefore follows
that these bright stars from system,
whose separation from that of those OF
the fainter stars is marked by the
change of relative numerical frequency.
What, then, is the shape of this sys-
TEN? and have we any dependent proof
OF its existence? Sir Sohn Herschel
and Dr. Gould have pointed out that
there is in the sky a belt of brighter
stars, which is very nearly a great cir
Gle of the sphere. This belt is plainly
marked, and it is inclined about 80 de-
grees to the milky way, which it cross
es near Cassiopa and the Southern
Cross. Taking all the stars down to
the fourth magnitude DIR. Gould shows
that they are with reference to the
milky way. In fact, TIE belt has 264
stars on one side of it and 263 on the
OJncf, WHllc Lne corresponding NUMBERS
for the milky way are 245 and 282.
From this and other reasons it is con-
cluded that this belt contains brighter,
stars because il contains the nearest
stars, and that this set of nearer and
brighter stars is Gistinctively the clus-
ter to which our sun belongs. Leaving
out the brighter stars, which may be
accidentally projected among the true
stars belonging to this cluster, DR..
Gould concludes that our sun belongs
TO cluster of about 400 stars; that it
lies in the principal plane OF the cluster
(since the belt of stars is u great, not
small, circle), and that this solar clus-
ter is Independent of the vast congeries
of stars, which we call the milky way.
We know that the sun is moving in
space. 1t becomes a question whether
this motion is one common to the solar
cluster and TO the sun, or only the mo-
tion of the sun in the solar cluster. But
a very important research will be to in
vestigate the solar motion without en-
ploying these 400 stars as data.