Republican farmer., 1918-02-01

The area of sky lying between the
zenith and tho southern horizon con-
taIns the very finest aggregation of
stellar beauty that the celestial sphere
can show. Practically in the zenith
is Capella, the bright pride of the con-
stellat1on of Auriga, the Charioteer, a
pure white star which is almost as
brilliant luminary as Vega of the
Tyre. Capella is rated by the astron-
omers as of the magnitude plus one
fifth" approximately twice as bright
as the standard first magnitude. Of
all the stars visible to us who live
in the northern extra-tropicaI lati-
tudes it ranks third.
Our scientists have discovered a
Eumber of very interesting things
about Caoella. Its distance from the
earth is so great that, in spite of the
fact that it appears insignificant com
pared with our sun, it is really a star
which is radiating heat and light 200
times as strongly as the sun. The
actual distance is computed to be no
less than 2,700.000 astronomical units.
This omit is n small distance itself
being no less than the distance of the
Garth from the sun, or $4,000 900
miles. Multiply those two figures to-
gether AMI you will have the distance
in miles separating US from CapeIla.
No wonder that SO much of the radia~
ted energy of the star is lost to US.
Furthermore the spectroscope has
shown that what appears as a single
star to US is really a system composed
of two, revolving about their COM
mon center of gravity in about one
hundred days.
Castor and POllux
East of Auriga are the heavenly
twins, Gemini, the two brightest stars
; of which are called Pollux and Castor.
They are very nearly of the same
brightness, but Pollux has q little the
better of it. Several hundred years
ago, when the astronomers of that
day made new classification of the
stars, they called the brightest OF
each group alpha, the next brightest
beta and so on down the Greek
alphabet. They called Castor alpha
Gemini," which shows that at that
time Castor must have been the
brighter of the two, whereas today
, the reverse is the case. It is not adj
missible to think that the old astron-
omers were mistaken, for they were a
set of very keen and able observers
The modern astronomers have the
, great advantage over them of possess
, ing instruments such as they hardly
dared even to dream of.
The only conclusion which we can
properly arrive at is that the relative
brightness of the two stars has under
gone a change. It is an extremely
interesting case, as changes in bright
, ness or position among the so-called
fixed stars are very rare indeed. The
astronomers of succeeding ages will
have the great advantage of the ac-
, Icurate and complete GAIA wa1cH IS be-
ing kept today. Judging by past his
4 tory they will also have instruments
of far greater precision and undoubt-
n eddy of q greater power than those
which we possess. To them the twins
may be very far from deserving that
name, for we do not know whether
it is Pollux or Castor that has under
gone a change.
In spite of not being the brighter of
|, the two, Castor is the more interest
ing, for what appears to us as one
single body is really made up of four.
e Even a telescope Of modest dimen-
= sions can separate the two major
= components, but it was only by means
/ of the far more delicate spectroscopic
l tests that each one of these in turn
D was found to be composed of two sep
: arate parts.
Orion the Great Hunter
/ 1t will pay you we'll to become
thoroughly familiar with the gre +
1 group of Orion, since it is withOLL
Y doubt the most impressive as well as
i one of the best known consultations
= in the entire armament. It's appear
!, ance is so characteristic that there
= should be no difficulty in learning and
? recognizing it at any time that it is
above the horizon. At the time of our
map this month it is on the meridian,
about half way between the zenith
and the horizon in the best possible
tposition for observation. There you
will see three bright stars about equi-
distantly placed on a line practically
. parallel to the horizon; to the north
ward, little higher in the sky, is the
= reddish Betelgeuze, to the southwark
e the brilliant star Rigel. All these
/ stars are of the group Orion. The
: first mentioned three stars are the
3. famous Belt of Orion, the star Betel-
s gueze marks the hunters right Shout
: der and Rigel his left foot. Hang
: ing from his belt is the jeweled scab-
r bard of the sword, marked by the
:. fainter line of staBs running off from
i the southern end of the belt in the
o general direction of Rigel.
t If your eyes are sharp and the at
, Imospheric conditions particularly
: good, you may notice that one of
n these stars in the scabbard is a bit
g hazy; it is a nebula, the Great Nebula
: in Orion, than which no finer sight
: is revealed by the astronomers tele-
scope. If you have even a small in
lstrument at your disposal and turn
lit upon this object, you will be amply
rewarded by the view of a cIoud-like
mass, itself family luminous and cas-
n ily distinguished from the black PACK
= ground of the sky beyor[. In the
area occupied by it are many small
. stars, among them a group of -four
II called the Trapezium, which very
l. likely raay be Intimately connected
with the structure and development
l. of the nebuia and its possible evolu-
IT tien into a system of planets and ont
- OF more suns resembling our own.