Alma record. (Alma, Mich.) 1878-1928, 1889-01-04
Astronomical Facts.

The UranOmetrla Nova, M Arge-
landa. gave the positions of the lucid
stars OF the northern sky, and it has
been supplemented by the Uranome-
tria Argentina OF DR.. Gould. which
covers the southern sky. With the
stellar statistics Of TIE 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
1 TO the situation OF our solar system IN
relation to them. The outline OF his
reasoning is given by writer in Serb
ner's. In the first place it is fairly
! proved that in general the stars that
are visible 10 the naked eye Che lucid
/ stars) are distributed at approximately
! equal distances one from another and
| that, on the average, they are Of APP
proXimately equal brilliancy II we
make a 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 10 fourth magni-
! tudes) than of the fainter (from fourth
To seventh magnitudes). That is, there
| is an unfailing and l1nsystcmatic 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 N
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 belt of brighter
stars, which is very nearly great cir
Gle of the sphere. This belt is plainly
marked, and it is inclined about so de
grees to the milky way, which it cross
es near Cassiopa and the Southern
Cross. Taking all the stars down &c
the fourth magnitude DIR. Gould show:
that they are with reference TO the
milky way. In fact, the belt has 20
stars on one side of it and 263 on the
other, while the corresponding numbers
for the milky way are 245 and 2S2
From this and other reasons it is con
Guided that this belt contains brighter
stars because j. contains the nearest
stars, and that this set of nearer anC
brighter stars is cistinctively the clus
ter to which our sun belongs. Leaving
out the brighter stars, which may DC
accidentally projected among the tru,
stars belonging to this cluster, DR.
Gould concludes that our sun belongs
to a cluster of about 400 stars; that i
lies in the principal plane of the cluster
(since the belt Of stars il 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 il
space. 1t becomes question whethe
this motion is one common to the solal
cluster and 10 the sun, or only the mo
ton OF the sun in the solar cluster. Blu
a very important research will be to in
yestigate the solar motion without en-
ploying these 100 stars as data.