Evening star. [volume] (Washington, D.C.) 1854-1972, 1896-08-01
TRAMP
ECLIPSES BOOKED TO OCCUR

Five stars of the first magnitude will be
above the horizon at o'clock this even
ing. They are Vega. in the Tyre. nearly
overhead Arcturus, in m.dheaven in the
west; Spica, at low altitude between west
and southwest; Antares, the Scorpions
Heart" between south and southwest, at
about one-fourth of the distance from the
horizon to the zenith. and Affair. in the
Eagle. at about two-fifths of the distance
from Vega to the southeastern horizon.
The brilliant orange-yellow star which
may be seen about midway from Spica to
Antares, and which forms with Spica and
Arcturus large triangle with two nearly
equal sides, is the planet Saturn.
The stars should all be identified readily.
and they will aid in locating the constella-
lions indicated on the planisphere. OBJ
serve that Hercules and the Northern
Crown lie between Vega and Arcturus;
Ophiuchus, the Serpent-Holder. is be-
tween Vega and Antares. his head. bright
rather more than third of the distance
from the former to the latter star; below
Nega-between 1t and the northeastern
horizon-is the Swan. or Northern Cross:
between Hercules and the Pole Star is the
Dragon, the eyes of which are in line
between Vega and the Great Dipper now
low in the northwest. In the northeast at
about the same altitude as the Dipper. Is
the W-shaped figure of Cassiopeia. The
Square of Pegasus has but just fairly risen
little north of east. and Andromea re-
cines upon the northeastern horizon.
One of the most interesting of the stars
now in a favorable position for observing
a star about which good deal has lately
been said in astronomical circles-is that
known from its number in Flamsteed's
catalogue as 20 Ophiuchi. 1t is a star of
the fourth magnitude near the right
shoulder of Ophiuchus, and now crosses
the meridian at about o'clock. 1t is the
most easterly of three stars of about the
same brilliancy to the left of the third
magnitude star which marks the shoulder.
Remarkable Star.
A small telescope will show that 20
Ophiuchi is double star. having a rose
colored companion of about the sixth mag
nitude. 1t Is an extremely pretty object
for such an instrument. 1t Is. further
more binary star, that is to say, it
is not merely double, but the two compon-
eRts are revolving round each other, or,
rather. around their common center of
gravity, like pair of dumbbells thrown
into the air Although it Is one of the most
easily observed of this class of stars-per-
haps for this very reason-it has given as
tronomers no end of trouble. Repeated
attempts have been made to determine the
orbit of the companion star and to ascer-
tain the period of its revolution, but all
such attempts have. until very recently.
been signal failures. The star has sue
maticians. No sooner has an 'orbit been
assigned to it than it has proceeded to
start out on a new route of its own devils
ing. In 1872, ninety-three years after its
discovery by the elder Hersc he'll it had per-
formed a complete revolution round its
primary; but in so doing 1t had carefully
Stunned every one Of the tracks that had
been laid down for it by astronomers. and.
is now known, it was considerably be-
hind its true schedule time
This obstinate star. 20 Ophiuchi. which
has so long played fast and luose with the
English and German mathematicians, has
firally been corralled, SO to say, by young
American astronomer, DR.. See. of the Uni
versity of Chicago. AS long ago 1913
conjecture was ffazarded by an English as
tronomer. Capt. Jacob. that there was in
this system a third and Invisible body.
which was creating all the disturbance, and
Sir John Hersch.l, one of those who had
wrestled with the star unsuccessfully, was
inclined to the same view. Dr.. See has
worked upon this superstition. With in
finite plans and with an amount of labor
which would seem fabulous to one whose
notions of the higher mathematics" are
derived from even the most intricate of
commercial problems, he has computed an
orbit for the companion of 10 Ophiuchi,
which he believes will be found to be en-
tirely satisfactory to the star. SO that we
shall have no further trouble from it, Ac-
cording to DR.. See, this companion star is
attended by dark satellite, the mass Of
which must be very considerable, and which
revolves around the star in a period of
thirty-six years, while the two together
perform revolution around the larger
star, in highly elliptical orbit. in a period
of Lightweight years. Those most compe-
tent to judge are of the opinion that DR..
See has solved the problem. few years
will suffice to decide the matter beyond a
doubt.
Law of Grnyftntion.
But why 50 much anxiety over the
behavior Of an insignificant little star, and
why so much rejoicing as there is over the
solution of the mystery? The problem in
wolves vastly more than On its face 1t
seems to do. In the first place, the law of
gravitation itself is still on trial IT has lot
yet fully demonstrated that this law, as it
has been learned from study Of the solar
system, is universal in Its application, al
though there are probably few. if any, as
tronomers whose doubts upon this point
are very serious. The orbital movements
of the distant stars afford just the data
needed 20 set this question definitely at
rest. If these stars are found to move as
they should do in obedience to the law of
gravitation all doubts that the law is oper-
alive where they are must vanish In the
second place, these binary systems. which
differ In so striking manner from our
tain the clue to some important questions
relating to the origin of star systems In
general. Eventually. it is thought, they
will throw strong light on the history Of
creation, the grandest of the problems at
which astronomy is now at work. All in
formation that can be obtained about them
is: therefore. cheap at whatever cost.
another mite to the slowly accommodating
mass Of evidence that space abounds in
non-lunlinous as well as luminous worlds.
Fifty or more years ago Peters and Bessel
concluded. from certain irregularities in the
proper motions Of Sirius and Procyon that