Evening star., 1939-05-05
BY THOMAS r. HENRY.
Star Sta6 Correspondent.

BY THOMAS r. HENRY.
Star Stan Correspondent.
FORT DAVIS, Tex, May 5.-The
billion-star Milky Way galaxy, in
the density Of which the sun and its
tiny planets are buried, is surround d.
ed by a 100000, ,000, ,000, 900 900 mile
thick atmosphere of light, hot stars
growing thinner and thinner as 1t
diminishes into the almost absolute
emptiness Of interglactic space, 1t
was revealed here today by DR..
Harlow Shapley, professor of as
tronomy at Harvard University.
DR.. Shapley reported at q SYM
postum on mans latest advances in
knowledge Of the totality of crea-
ton, attended by a group of the
worlds foremost astronomers, at the
dedication of the Mcdonald OBJ
servatory in the West Texas Noun
tains. Sponsored jointly by the Uni
versities Of Chicago and Texas, its
telescope now is the second largest
In the world.
Star System Rediscovered.
The Harvard astronomer also re-
vealed for the first time the recent
discovery of two curious star systems
In the Southern heavens. Unlike
anything known in the universe be-
fore these gigantic masses Of stars
in the consultations of Sculptor and
Forxas are within less than 100000
light years from the edges of the
Milky Way and increase to nine the
number Of star systems in the local
supergalaxy." This includes all the
independent star clouds within q
million light years of the earth. The
largest Of these objects is the Milky
Way itself. It has two smaller but
Independent companions, the greater
and lesser Clouds of Magellan seer
only in the Southern Hemisphere.
There are two other galaxies of COM
parable size to the Milky Way, three
smaller star clouds and the systems
Just discovered.
These latter, DR.. Shapley said,
seem to be about half way in size
and density between the Magellanic
clouds and "spheroid galaxy" such
as the Milky Way itself. Their dis
tances have only just been measured
ut Harvard and at the Mount VIII
son Observatory Of the Carnegie In
stitution Of Washington, due to dis
covery in them Of so-called cepheid
variables whose pulsations, depend
Ing on mass and brightness, consti-
tute the yardsticks of the universe
About three times as far away as the
Clouds Of Magellan. they might be
considered the next nearest CONT
nents Of light in the seas of space.
beyond the coast archipelagos.
Surrounded by Stars.
Hitherto the Milky Way system
has been pictured as an elongated.
lens-shaped conglomeration of stars
and star systems. about 5000 light
years in width with sharp edges
ending abruptly against empty
space. It now must be considered,
DR.. Shapley said, as surrounded by
. spheroidal envelope of stars, hun
dreds Of light years apart-just as
the earth is surrounded in a gaseous
atmosphere. This discovery increases
the volume, although not the weight,
Of the galaxy many fold.
The greatly diffused stars within
this envelope all are light and are
moving at speeds averaging around
$50 miles a second. This is much
faster than the stars like the sun
which are included In the main mass
OF the galaxy. It is highly probable
DR.. Shapley said, that this atmos-
phere has been evolved in the last
few billion Years with the gradual
escape Of one light star after an
other from the attraction of the
center. Some Of them already may
be so far or that they are escaping
from the galaxy's gravitational pull
with the possibility Of escaping into
space altogether, as atoms of very
light gasses such as hydrogen have
escaped from the atmosphere of the
earth.
Concentrated in Disk.
Approximately 80 per cent of all
the Milky Way stars, DR.. Shapley
said, appear to be concentrated in
the disk. This concentration in
creases toward the center, forever
hidden by black dust clouds, but
the distribution Of stars in the
neighborhood of the sun, where they
are about five light years from each
other, gives a fair idea Of the aver
age. The galactic atmosphere is q
hundred times thinner than this.
Within this galactic atmosphere,
DR.. Shapley pointed out, move about
100 globular clusters, great masses
Of stars which are related to the
major system like the planets to
the sun. The Clouds of Magellan
also impinge on the galaxy's atmos-
phere and might be considered as
satellites.
Recent studies have shown, DR..
6hapley said, that the nearest of
the external galaxies, the so-called
Andromeda nebula, whose light re-
quires less than a million years to
reach the earth, also is inclosed in
a thin star envelope. It's total di-
mensions turn out to be slightly less
than those Of the Milky Way galaxy,
the atmosphere being about 10000
light years in thickness. These find
ings have been made possible, DR..
Shapley said, through the use of the