Evening star., 1951-04-20
Hot Red Sturs Traced
In Clouds ofMogelIon
HoIf-MiIIion Times Brighter
Than Sun, Astronomers Find
By Thomos R. Henry

There are stars nearly half billion
miles in diameter and 100000 times
brighter than the SUM-
These are extremely hot red stars
in the two Clouds of Magellan in the
skies nearly over the South Pole of the
earth. They are reported by DR.. Harlow
Shapley, professor of astronomy at Har-
ward, as result of a systematic survey
Of the southern heavens at the univer-
sity's South African observatory.
Some of these stars easily would fill
the orbit Of the planet Jupiter around
the sun. They exceed both in size and
heat anything yet discerned in the
Milky Way galaxy, Of which the solar
system is part.
The Clouds of Magellan are vast
aggregation Of stars which lie outside
this 100 billion-Star system. They are
separated from it by approximately TOO
billion miles of empty space and their
light travels more than 100 years to
reach the earth. They are galaxies them
selves, similar in nature to the Milky
Way galaxy, but very much smaller.
cloud and the small cloud. They
ton outside the Milky Way.
Observable as Whole. 81.
They offer the great advantage, DR..
Shapley says, of being observable as
whole from convenient distance easily
within the range Of the South African
telescope. The observer inside this
galaxy finds himself quite often unable
to see the woods for the trees. Observa-
ton of the Clouds of Magellan, however,
is more like standing on hilltop and
looking at isolated patches of woodland
below. Individual stars can be dis
eliminated in both clouds.
1t is now clear. DR.. Shapley explains,
that the brightest star in the universe
is bright-blue star in the large cloud
whose luminosity, allowing for distance.
is about a half million times that Of
the sun. None quite as bright has yet
been found in the small cloud. although
some exceed the suns brightness by
nearly 300,000-fold.
These constitute a type of objects as
yet unknown in the Milky Way galaxy.
This is not valid reason for believing,
DR.. Shapley points out, that such OBJ
jects may not exist in the system, but
they are hidden because of the very
proximity of the observer, and the great
dust clouds which exist in galactic space.
The brightness of star like S. Doradus
has been reached in the Milky Way
galaxy, so far as known, only once in
the time of man.. This was in 1865
AID. when star explosion. of the type
known as supernova, was recorded by
Chinese astronomers. A hitherto in
significant star, probably about the size
of the sun, attained about million-fold
its ordinary brightness in few days
and then rapidly faded to insignifcance
again. - s. s-.-taa
Magnitudes Deduced. s,.
The Harvard astronomers observa-
tions to date have been confined to the
red-colored super-giants in the small
cloud. The average picture would seem
to be that of the great star Betelgeuse
IN the constellation of Orion, largest
known star in the Milky Way galaxy.
From comparison with these, the mag
nitudes of the brighter ones in the out
side galaxy can be deduced.
1t is quite likely. DR.. Shapley believes,
that similar objects will be found in
other smaller outlying galaxies in the
. local family of star systems, Of Which
only one is comparable in size to the
Milky Way galaxy. ssas
The studies have otherwise led to the
conclusion. it is reported. that the large
and the small cloud are quite different
kinds of astronomical systems The
former observations show, is full of dust
which obscures light from galaxies ly-
ing beyond it in space. The same is
true of the Milky Way galaxy. Out Of
this dust new stars continuously are
being created. The small cloud, how
ever, seems nearly dust-free This leads
to the conclusion that one is young
and the other an old system. The small
cloud apparently has come to full
maturity.