Evening star., 1902-08-30

formation, having. apparently, no great
thickness In comparison with its breadth
Ihat Is to say, the millions of telescope
stars which form its groundwork are all at
essentially the same distance from us
What is this distance? Are these stars
really the small bodies that they appear TO
be- or Is their faintness due to their enor-
nous remoteness from us? Again does the
Milky Way belong especially to us-does IT,
together with the few hundred of the
brighter stars which may be supposed to be
encompassed by II, constitute our universe
which may be only one OF hundreds or
thousands of "universes," or is II al so vast
a distance from our solar system that IL
must be regarded as something entirely be-
yond our special section of the great uni
verse of worlds? These questions are at
present unanswerable. The prevailing opin-
ion among astronomers now is that these
Milky Way stars are bodies comparable in
SIZE with our sun, and that consequently
they must be at a distance of hundreds
perhaps thousands OF light years from
us to shine so family they do. On the
other hand. many astronomers see reasons
for concluding that their distance from us
Is not great, as star distances go. and that
they are really bodies OF relatively insig-
nihcant size.
The Demon" Star.
The variable star Beta Persei, better
known as Algol. the Demon, is now at
pm. well above the northeastern horizon
and for several months to come 1t Will be
situated favorably for observation. The
popularity of this star is that after shin
ing for about two and a half days as a
star Of the second magnitude 1t begins to
decline in brightness. and in about four
hours it has descended nearly to the fourth
magnitude. 1t then begins to brighten and
al the end OF another four hours II is again
a star OF the second magnitude, thus TO re-
main for another period OF two and a half
~ 40 Il
OF the star is now known to be the reyolu-
ton round ii Of dark companio or satel-
lite, which passing periodically between it
and US cuts on portion OF its light. The
exact period Of the revolution, determined
from long observation, is DAYS 20 hours
~ minutes, So seconds. Two minima Of the
star at hours favorable for observing vM
occur this month. On the 18th 1t will ,-gin
TO wane at about pm, eastern standard
time, and will be at its least brilliancy at
IL pm: the next minimum will occur on
the 10th at 7:JO pm.
The Planets.
Mercury has been an evening star sincs
August 10 and will continue to be such
through this month, reaching its greatest
elongation or apparent distance east from
the sun on the oath. 1t is now on the south
side Of the equator and therefore in its least
favorable position for observation though
for a few days before and after the cath II
should be visible on clear evening low in
the southwest.
Venus continues to be a morning star but
Is too close to the sun to be visible
Mars also Is morning star, rising on
the 1st of the month about three hours be-
fore the sun, north Of east.
Jupiter and Saturn are both evening stars
In the positions already indicated Both are
now favorably situated for observing with
telescope. except for their low altitude for
observers in the northern hemisphere. Uran-
u.s. near the star Theta In the right foot
OF Ophiuchus, may be seen with the naked
eye on clear moonless night, but is not
easily found without the aid of a chart
On the 23d, at pm, Washington mean
time. the sun will pass into the southern
hemisphere and autumn will begin.