Evening star., 1898-09-03
OF the stars-is the ambitious aim OF tn.
New Astronomy
EcIipsed by "a Satellite.

OF the stars-is the ambitious aim Of tn,
New Astronomy.
EcIipsed by "A Satellite.
The variable star AlgoI in Perseus. has
been pointed out. From now on for sew
eral months this star will be favorably SIT
uated for observation. Its popularity is
that after shining for about two and a half
days a star of the second magnitude Il
falls in the space of about four hours to
the fourth magnitude, and in the course of
the next four hours 1t RECEIVERS its usual
brightness. The cause of this change OF
brilliancy has now been clearly shown to
be the fact that the star IS attended by a
dark satelite which revolves around il in
a period, to give it exactly, OF two days
twenty hours forty-nfne minutes, and
which passing periodically between us and
Ii cuts of a portion of its light On four
evenings Of this month Algol will go
through its changes at seasonable hours.
On the 9th Ii will begin to wane soon after
D.m-, and will be at a minimum an hour
after midnight Other minima will occur
the 9Th, at 10 pm, on the 18th, at p.
m. the 18th. at Il pm
There are nine other stars-varta hles OF
the "Algol type" that is, stars which IN
dergo at regular short intervals partial
extinction of their light. but with the eN-
ception of Algol they are inconspicuous
stars-some of them telescopic-and their
change is not great. All of them are inter-
esting. however, from the fact that they
furnish direct evidence, in addition TO much
indirect evidence, that space abounos IN
non-luminous as well luminous worlds.
Over 300 variable stars are now cata-
logued, exhibiting the greatest variety OK
eccentricities in this respect their changes
of brilliancy being IL many cases apparent
ly quite capricious. No generally accepted
explanation of their behavior-except in
the case of the AlgoI stars-has as yet
been given They are still among the enig-
mas Of astronomy
Venus is now the reigning evening star.
It has been such since February l5, and
in the interval since it first became visible
it has steadily increased in brilliancy until
now 1t shines with that surprising ra-
dance which won for it centuries ago the
tribute Of Homer as '-the most beautiful
star that stands in the heavens, as II
certainly is.
one would suppose that Venus would he
a superb object for the telescope. In fact,
it is one of the most difficult OF celestial
objects of which to obtain a satisfactory
view. Its dazzling brilliancy brings out
every defect which the telescope may have,
and, besides. owing to its nearness TO the
horizon after sunset, it is always more or
less affected by atmospheric disturbance
For these reasons the best views Of Venus
are obtained in the daytime. Then. IL
is seen with its light subdued upon back
ground of blue sky, il is indeed a beautt-
full object, closely resembling the moon
seen with the naked eye under the same
circumstances, with the difference that IL
is free from the dark blotchss which dis
figure the moons face.
Characteriktics Of Venus.
Very little is known respecting the phys
icaI condition of this planet It is known,
however, that Venue is enveloped in an
atmosphere which seems to be more dense
than the earth's. 1t is, in fact. because OF
its atmosphere that so little is known about
the planet. This atmosphere forms an al
most, il not quite, impenetrable veil, which
effectually conceals the planets surface
markings that astronomers have not yet
been able to determine with certainty the
period OF its rotation on its axis. This ques-
tion has lately been much discussed among
astronomers. some maintaining that the
planet rotates in about the same time as
does the earth, while others are equally con-
fident that its rotation period is the same
as that of its revolution in its orbit-about
Do days. In this latter case il must al
ways turn the same hemisphere to the sun,
as the moon always presents the same face
to the earth, or in other words, over one
half of the planet there must be perpetual
day and over the other half perpetual
night. The weight of the evidence seems
to be in favor of this latter view whicn
was first suggested by M SchiaparelH in
1896, and has the support of several COM
petent observers, though others with
equally good regulations are either nom
conmittaI on the subject or hold that the
short period is the more probable.
Morning Star.
Mercury will be morning star after the
9Th of this month. 1t will be at its great
est distance (apparent) west of the sun on
the Dist.
Mars is now near the western border OF
the constellation Ciemini and rises at about
midnight. Some twelve or fifteen degrees
west OF Mars is Neptune, away below the
limit of the naked eye
Jupiter Is still an evening star, but his
present season sucn is now practically
closed He sets before pm
Saturn is evening star in the ScornIo,
about ten degrees northwest of Antares
He sets soon after pm. Uranus. invisible
now TO the naked eye, sets half hour be-
fore Saturn.
On the I'D of the month at p.m. Wash
lngton time, the sun will cross the line
entering Libra, and autumn will begin