Sacramento daily record-union., 1888-09-08
OUR SOURCE OF LIGHT.
Prof. Holden Tells of the Cluster OF ST.;
to Which Our Sun Yelnnpa

"The UrGnometiia Nora of Argelanler
gave the position of the lucid stars of the
northern sky, and ithas been supplemented
by the Uraaometria argentina of DR.. Gould,
which covers the southern sky. With the
stellar statistics of the whole sky before
him, DR.. Gould was i'll Il position to draw
some extremely interesting conclusions
with respect to the arrangement of the
brighter stars in space, and to the situa-
ton of our solar system in relation to
them. The outline OF his reasoning can
be siven here, but the numerical evidence
upon which his conclusions are founded
must be omitted. In the first place, it 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 approximately
equal brilliancy. If we make table of
the number Of stars of each separate mag
nitude in the whole sky we shall find that
there are proportionately many more of
the brighter ones from first to fourth
magnitudes) than Of the fainter from
fourth to seventh magnitudes). That is.
there is an uniailing and systematic ex-
cess Of the observed number of the
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 10
fourth magnitudes (some 500) are really
nearer to us than the fainter stars. 1t
therefore follows that these brighter stars
form 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 system
and have we any independent proof of its
existence? Sir John Herschel and DIR.
Gould have pointed out that there is in
the sky belt of brighter stars which is
very nearly great circle of the sphere.
This belt is plainly marked and it is in
clined about 500 to the Milky Way, which
it crosses near Cassiopea and the Southern
Cross. Taking all the stars down to 40
magnitude DR.. Gould shows that they are
more symme trically arranged with refer
ence to this belt than they are with refer
ence to the Milky Way In fact, the belt
has 264 stars ON one side Of it and 263 on
the other, while the corresponding num-
bers for the Milky Way are 245 and 2S2.
From this and other reasons it is concluded
that this belt contains brighter stars be-
cause 1t contains the nearest stars, and that
this set of nearer and brighter stars is
distinctively the cluster to which our sun
belongs. Leaving out the brighter stars
which may be accidentally projected
among the true stars belonging to this
cluster, DIR. 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 bright stars is a
great, not small circle) and that this
solar cluster is Independent of the vast
congeries of stars which we call the Milky
Way.
ave know that the sun is moving in
space. 1t becomes question whether this
motion is one common to the solar cluster
and to the sun, or only the motion of the
sun in the solar cluster. The motion has
been determined on the supposition that
the sun is moving and that its motion is
not Systematically shared by the stars
which d.. Gould assigns 10 the solar
cluster. But very important research
will be to investigate the solar motion
without employing these 400 stars as
data, September Century