Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1889-03-02
THE WINKING DEMON.
A Remarkable Variable Star With a
Collision Pending.
BEAUTIES OF A WINTERS NIGHT.
Something About the Great Mysterious
Nebula of Orion.
THE PLANET SIRIUS. TIE SUNS RIVAL
rwn1rrEN FOR THE DIsrArcH.i !

WRITTEN FOR THE DIsPATcH.i
1t may probably be considered an unfor-
tunate circumstance that the most interest
ing consultations and brilliant stars are to
be seen in the winter, and the amateur as
tronomer who is unwilling to brave the cold
blasts in order to study the beauties of the
winter sky must miss great treat.
As the motion of the celestial sphere is not
clearly understood by everyone, few
words of explanation may be appropriate.
If we stand in an open space on clear
night and watch for a short time we see
stars rising in the east and setting in the
west, and those in the south moving west
ward, while if we turn our eyes to the north
we notice that if we take point in the
heavens about half way from the north
point to the point overhead, stars above this
point are moving toward the left, and stars
below toward the right, while those on the
lett are moving downward, and those on the
right upward.
THE POLE STAR.
In fact, stars in this region never set, but
describe small circles about point in the
celestial sphere elevated, in our latitude,
about forty degrees above the north point.
This point is called the north pole ofthe celes-
tial sphere, and is marked by star of the
second magnitude, Polaris, or the Pole star,
which is known to everybody. This star is
only degree and a half from the true pole,
so that it describes very small circle and
thus appears stationary.
All the stars revolve in circles around
L.. l. r - -. IL
SO large, on account of their distance from
the pole, that portions of their orbits lie
below the horizon and these stars rise
and set. OF course this motion is
all apparent, and is due to the rotation of
the earth, which is accomplished in % hours,
56 minutes, 40.9 seconds. Now, since the
suns revolution about the earth takes "a
hours (the time is longer than the time OF the
earth's rotation time on account OF the re-
tarding influence of the earth's annual revo-
luton about the SUM the stars gain on the
sun each revolution by an amount equal to
the difference between "a hours and % hours,
Sc minutes, 400 seconds, or minutes, 81. 81
seconds, so that each evening a given star
will rise about minutes earlier than it did
the previous evening. This amounts to 2
hours a month, so that the aspect of the
starry vault changes continually with the
season.
A BRIGHT WINTERS NIGHT.
1t happens that the portion of the celestial
sphere we see on a winter evening contains
more stars of the first and second magnitude
than any other portion, and it is due to this
that the winter sky appears more brilliant
than the Summer, as well as to the fact that
the atmosphere is probably clearer on a
cold winter night. The Greely expedition
found that near the North Pole stars fully
one magnitude below the limit of visibility
in our country could be seen.
If we stand facing the south about 7:30 in
the evening in the latter part of February
we see grand array of stars A little to
the west of south, and about half way from
the horizon to the zenith is seen an oblong
formed by four conspicuous stars, about 10
degrees long by 6 wide. The distance from
the horizon to the zenith is 80 degrees,
which will serve as a standard for compar-
ison. This oblong marks the constellation
Orion. Orion was mighty hunter in the
Greek mythology, and when he died they
placed him among the stars. A row of three
stars crossing the center of the oblong
diagonally marks the belt of Orion, and
below the central one of these stars a
vertical row of three smaller stars is seen,
making his sword.
NEBULA OF ORION.
If the middle one Of these three stars be
examined, it will be seen to be surrounded
by haze. This is the great nebula of
Orion, one of the most wonderful objects in
the heavens, and plainly visible to the
naked eye on clear moonless night. As
tronomers have turned their great telescopes
upon it, in the hope of resolving it into a
mass of stars, but they have been unsuc-
cessful, and spectrum analysis now leads us
to believe the great nebula is mass of glow
ing vapor The supporters of the nebular
hypothesis looked to this body as an exam
pie of the way in which q system of worlds
was to be formed out of an immense mass
of 'tfre mist" according to their theory, but
it does not behave just as the mass of fire
mist ought to. Orion possesses many other
object of interest, especially for the tele-
scopist, but they cannot be enumerated here
The star in the upper left-hand corner of
the obIong of Orion is Betelgeuse. Twenty
six degrees east of this star is seen another
bright star. Procyon. in the constellation
CAMS Minor, the Little Dog; lower down,
26o from Procyon and the same from Betel-
geuse, is Sirius, the Dog star, the three
forming an equilateral triangle 26o on o
side.
BEATS THE SUN.
Sirius is the brightest fixed star in the
heavens. He is two and one-half times as
bright as the average first magnitude star,
and must be vastly larger or more brilliant
than our sun, since his distance is so great
that it takes light, travelling at the rate of
1876. 900 miles per second, more than Is years
to reach u.s.
There was q mystery about Sirius for a
long time. He was observed to move about
in strange way. For few years he would
move in one direction, then he would move
in another direction. 1t was suggested that
the motion was due to a companion star,
which did not give enough light to be visi-
BILE, but which revolved around Sirius and
pulled him in one direction and another.
1t was even calculated in which direction
he ought to be from Sirius. This idea was
justified BY the discovery, in 1862, of a
tenth magnitude star in about the calculated
position. This faint star must be of great
size to SO affect Sirius, but its surface has
probably low light-giving power.
THE DOG DAYS.