The News-Herald. [volume] (Hillsboro, Highland Co., Ohio) 1886-1973, 1910-07-28
COLOSSAL. ARCTURUS
The Fourth Brightest Star In All
the Heavens.
IN REALITY A MONSTER SUN.

dred Times Larger Than Our Sun In
Diameter and Is About Nine Hun
dred and Fifty Million Miles Distant.
Most Of us are prone to think of our
sun as being the largest body in the
heavens, the grand high lord Of all the
little planets and the twinkllng stars.
Such is very far from being the case.
Practically all of the fixed and twin
king stars are as large as, and some
even larger than, our own sun. They
appear small only because of their great
distance, for they are just as truly
suns with families of planets flying
around them as is our central orb.
There is one of these stars I'm par
ticular that has attracted the atten-
tion Of astronomers, not only on ac-
count of its great size. but also its
enormous distance from our solar sys-
TEN. This Is the star Arcturus. To
have some conception Of the almost in
conceivable distance that separates It
from us the astronomical standard OF
measuring distance must be compre-
hended. Now, light does not come
from a luminous body instantaneously
TO our eyes. 1t takes time to come,
because II IS wave motion in a
medium. The velocity of light as
most recently determined is about
10000 miles n second. Multiply this
by the number of seconds in q year
and we have distance known in as
tronomy as light year. Therefore
when a star Is, say, six trillion miles
away we say 1t is one light year off,
which means that the light from the
star takes one year to reach us. II
may be of some interest to know that
there Is no fixed star less than ten
light years away, or sixty trillion
miles. This is the one known as Alpha
Centauri Most Of the stars are much
farther evep than that, Arcturus being
the farthest one measured to date.
Arcturus Is thought to be at least
hundred times larger than the sun
In diameter That would make it
10000 times larger in surface, or the
dimension that is ordinarily compared
BY means of the photometer its bright
ness has been determined to be $500
times that of the sun Ii Is the fourth
brightest star In all the heavens, Siri-
us, the dog star. being first in bright
ness. As regards the distance from
US. 1t has been found to be little over
160 light years, or $50 trillion miles.
This distance, of course. cannot be
conceived by mortal man, 1t is so stu
pendous and amazing. However, one
can get slight idea of it by means Of
an everyday analogy. Think Of the
fastest express train going at the rate |
of 100 miles an hour toward such a
star and compute the time 1t would |
take 1t is found to be in round mum
bers exactly 120OO0,OOO years! Now, |
as we know that II has taken its light !
so long to come to US and as there are |
a great many stars whose distance |
has never been measured exactly, but |
which have been computed to be ap-
proximately several million light years
away, we have absolute proof Of the
great age of the world and the stellar
universe.
The elements composing the sun Are
turus are, peculiarly enough, very
nearly the same as our sun. As 1t Is
one of the most wonderful and as
founding things that a scientist can
tell what a star so far away Is COM
posed Of, small explanation Of the
modus operandi would not come amiss
here. II is done by means of a small
instrument known as the spectroscope
which consists of glass prisms SO ar
ranged as to split up the light falling
on them into Its constituent parts.
Now, every substance has the power
10 cause certain color or line in the
spectroscope If 1t is in luminous con-
dition, so this instrument Is simply
pointed at the star whose composition
is sought, and If any line is found that
to a substance that we
know about we assume that this sub
stanI IS found in the star examined.
Another interesting thing is the meth
cd pursued in determining the great
by determining their parallax or angle
made at the star between two rays
from the star striking at two differ
ent points IN space. AS the greatest
distance that we can measure off In
this way and still take the angle is
the diameter Of the earth's orbit, that
distance is invariably used 1t is al
most 200,000O00 miles, but that, as is
seen, is very small compared with the
enormous distance Of the star. Now,
the angle thus measured from Arc
turus is only two-hundredths Of sec
ondl When 1t is remembered that
there are 90 seconds In a minute, 60
minutes in a degree and 800 degrees
In circle, 1t is at once seen what q
small angle the parallax is and how
careful the astronomer has to be In
his observations. Indeed. for a long
time, before modern delicately meas
uring instruments were invented, no
stars distance could be found, for
there was seemingly no angle formed,
and thus the old scientists had to as
sumo the star to be at intinity.-Pitts-
burg Dispatch