The Forest Republican. [volume] (Tionesta, Pa.) 1869-1952, 1889-08-14
The Cluster of stars to Which our
Sun Belongs.

"The UrdnonlctriG NoUd of Argeland-
er gave the positions of the lucid stars
of the northern sky, and it has been
supplemented by the Urdnonactria Arg-
entind of DR.. Gould, which covers the
southern sky. With the stellar statis-
tics of the whole sky before him DR..
Gould was in y position to draw some
extremely interesting conclusions with
respect to the arrangement of the
brighter stars in space, and to the situ-
alton of our solar system in relation to
them. The outline of his reasoning
can be given 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 distri-
buted ut approximately equal distances
one from another, and that on the
average they are of approximately
equal brilliancy. II we make q table
of the number of stars Of each separate
magnitude in the whole sky we shall
find that there arc proportionately
many moro of the brighter ones (from
first to fourth magnitudes) than of the
fainter (from fourth to seventh magni-
tudes). That is, thero is an 'unfailing
and systematic 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 500)
are really nearer TO us than the fainter
stars. Ii therefore follows that these
brighter stars form q 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 DR.. Gould have pointed
out that there is in the sky a belt of
brighter stars which is very nearly q
great circle of the sphere. This belt is
plainly marked, aud it is inclined about
so degrees 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 symmetrical
ly arranged with reference to this belt
Lndu lHtN are NllH ICltIeutt 10 INC
Milky Way. In fact, the belt has 264
stars on one side of il aud 263 on the
other, while the corresponding num-
bers for the Milky Way are 245 and 2S2.
| 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 distinctively 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 a cluster of about 400 stars; that it
lies in the principal plane of the clus-
! ter (since the belt of bright stars is o
| great, not a small circle) and that this
solar cluster is independent of the vast
congcries 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 aud to the sun, or only the mo-
tion 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 systcmatical-
ly shared by the stars which DR.. Gould
assigns to the solar cluster. But very
important research will be to inYesti.
gate the solar motion without employ
ing these 400 stars as data. "-ProteS
s0r Ea1Card S. Holden IN Century,