Warren sheaf. [volume] (Warren, Marshall County, Minn.) 1880-current, 1922-06-21
ASTRONOM ICAI.
OBSERVATIONS
Procession Of the Equinoxes
BY Levi G. johnson

Procession Of the EquinOxes
In connection with what said last
week concerning the gradual change
of the amount of the suns decli1ia-
tien north and south, Twill this week
endeavor to discuss the phenomena
known as the procession OF the
equinoxes. The cause Of both Of these
variations of the pointing Of the
earth's axis, for that is what it
amounts to, lies in the reciprocal ac-
ton of the earth and the other plan
cts. Being too Obstruse for me to
discuss in detail, will simply state
the effects and the general laws it
follows. About 1000 years ago when
the zodiac was divided into the now
familiar twelve signs, each sign being
marked by constellation bearing the
same! name, which is not the case at.
the present time, owing to the so
called procession of the equinoxes,
which is retrograde, i. e., east to
west, movement of the ,equinOXial
points along the ecliptic amounting
to about 50A sec. of arc per year or
deg. in about y years or nearly
one sign go deg.) in 1000 years,
hence the difference of place of the
signs of the zodiac and the constella-
ton bearing the same name. =
The two great circles spanning the.
celestial sphere, namely, the equator
and the ecliptic do not" coincide, but
intersect each other at two opposite
points. at an angle of about 231A de-
grees. This angle Is called the ;obli-
guilty Of the ecliptic.
TO understand the relations between
the equator and the ecliptic, we must
know the fact that the former is not
determined by. anything in the heav-
ems. but by the direction of the earth's
axis only; being the circle midway be-
tween the two opposite points which
lie in line with the earth's axis, and
known as the celestial poles; while
the latter is determined by the eartl1's
motion around the sun. Now the
shifting of position of the equinoxes
from year to year, does not arise from
anything going on in the heavens but
only from slow change in the di-
rection of the earth's axis. Since the
celestial poles are determined by the
direction of the earth'S axis, this
change in the direction of the axis
makes them (the poles) so around
circle in the heavens, having a ra-
dius of about 231l deg, the centre
of which is a point perpendicular to
the plane of the ecliptic, and requires
for a complete revolution about 26;-
900 years, consequently the equator
must simultaneously change its posi-
ton in regard to both the ecliptic and
the consultations in sort of Wab-
bling motion in the same period OF
time. The point in the ecliptic being
at present farthest north (231A deg
from the equator will 10000 years
from now be the same distance south
and vice versa. This explains the
constant shifting of position of all
the stars without exception, both III
regard to right ascension longitude
and declination Qatitude) which are
determined by the position Of the
equinoxial colure and the equator res
spectively.
The star Polaris North Starr is at
present about 1 deg. from the pole,
but the pole is approaching it and
will pass closely by it in about 200
years Some 1000 years ago there
was no north star, the star Polaris
then being over 10 deg. from the pole,
was not recognized as such. After
10000 years the pole will approach
the star Vega as close as about 5
degrees, while Polaris will then be
over 40 deg. from the pole, passing
very near our zenith in it's daily
diurnal motion.
The king Of the stars, Sirius, is at
present 25A deg. above our horizon
when in meridian, its altitude grad
ually decreasing from year to year,
so in about 5000 years it will entirely
disappear below the southern horizon
and will remain within the circle OF
perpetual occulation for over 11,OO0
years, after which time it will re-
appear. In consequence of the preces-
sion of the equinoxes the equinoxial
year sometimes called tropical or
solar Year, is 2OA min. shorter than
the siderial year Gas determined by the
stars) thus gaining one year in 10000
revolutions around the sun.
Astronomical Table for Week June rs
to July
(Standard time)
Sun Sun In Sun Moon
Rises Mer. Sets Rises
90 ~ .0n o.On 40