Helena weekly herald. [volume] (Helena, Mont.) 1867-1900, 1880-07-22

Providence journal. ]

lfrOVlQence Journal
The methods of finding the distances of the
stars of stellar parallax is one of the inter-
esting problems of modern astronomy. In
the days of old the stars were supposed to
hold the same position in regard TO each other
from age to age, and were therefore called
fixed stars to distinguish them from planets.
Nothing can be further from the truth. The
telescope shows that the stars are in constant
motion, but that the rate of motion is SO slow
that thousands of years must elapse before
the eye can perceive any change. Some
stars are coming toward US and some are re-
ceding from US. The Sun, which is only a
star, is movng, with all the planets in his
train. Our earth, which is but an atom
among atoms, is whirling, no one knows
whittier, through illimitable space. Even the
serene heavens above us this same space,
pervaded by an infinitely subtle ether, whose
particles are seething and surging like the
waves of the stormy sea. The motion of the
stars once established, it must follow that
some are nearer to US than others, and very
persistent and painstaking have been the eff
sorts to find out which of the shining suns
of space are our nearest neighbors.
Success, however, has crowned patient
labor. Among the $4,000, 900 stars that gilt
ter in the frmaInent, there are about dozen
stars visible in our latitude that have paral-
lax ranging frcm tenth to half second.
1t would be natural to suppose that the bright
est stars are the nearest, but this is far from
being the case. The nearest star in the north
ern heavens is double star of the fifth mag
nitude in the Swan, known as 81 Cygni. The
brilliant Sirius is nearly twice as far away.
The nearest star in the whole heavens is
Alpha Centauri, bright star near the south
pole. This has parallax of nine. tenths of a
second, and is twice as near as any other star.
Its distance is computed as more than 2OO,-
900 times our distance from the sun, or nearly
20, 600, 900 of millions of miles. If such be
the inconceivable distance separating us from
the nearest star, what idea can the finite mind
form of the immensely of space intervening
between us and the more remote?
Vigorous work is now being done in stellar
parallax by what is called Besselps method.
A star with proper motion, or one that has
been found to approach or recede from the
sun, is selected, and its position is compared
night after night, by means of the microme-
ter, with other small stars in the vicinity hav-
ing one proper motion, and therefore pre-
sumed to be further away. The star with
proper motion will change its position in re-
gard to the more remote ones when observed
from different parts of the earth's orbit. Some
interesting and intricate work of this kind has
been successfully completed at Mr.. Seagrave's
private observatory by Mr.. Waldo and Mr.
Seagrave. The problem was to determine
the parallax of star called Theta Cassiopeia.
This, by measuring its position and distance
from two small stars in the vicinity, was
found to be less than one-tenth of a second.
These enthusiastic astronomers worked upon
the problem from the first of September, 1878,
to the first of November, 1879. During that
time they made measurements of each star on
100 nights. A trained eye, keen perception,
and mathematical precision, as well as pa
tience and persistence, were involved in the
solution of this delicate and intricate problem.
These are the means by which astronomy has
won its most brilliant triumphs, and those
who would become practical astronomers
must give their nights to observation and their
days to study.