Evening star. [volume] (Washington, D.C.) 1854-1972, 1901-10-05

- N-e ONt"ueE -iS-oi. NJ - pm
hitherto been supposed. vogel deduces
from MS observations that the combined
mass OF the two stars which form the
double system is about four times that OF
the sun, and that the orbit in which they
circle around each other, or rather around
their common center OF gravity, is consid-
eraoly smaller than that of the planet
Mercury. Nogers conclusion. il confirmed,
VIII very probably explain certain irreg-
ularlty announced some time ago by Prof.
flckerlng to have been noted in the
doubling of the lines IN the stars spectrum.
At the Lick observatory.
-Four or five years ago Prof. W. W. Camp
bell. the present director of the Lick OBJ
servatory, began with the great telescope
OF that observatory a series of systematic
spectrographic observations. with special
list of some 325 Stars, for the purpose of
determining the velocities of the motion CT
these stars in the line Of sight'-thaJ is,
toward us or from us. One very unexpected
and very interesting result of this inycsti-
CATION has been the discovery that many
of these stars have a variable velocity,
which indicates that they have orbitai
movements-that they are "spectroscopio
binaries." Not less than thirty-one of the
stars Professor Campbelfs list have
been found to be Of this character. Among
them are the Pole star and the brilliant
Capella.
Campbell finds that the Pole star is not
merely binary, but is a triple system. The
variation of its movement is such u
indicate that the bright star circles about
an invisible companion lin a period of a
trifie less than four days, while this binary
pair reyolyes about a third dark body IN
an as yet undetermined period. probably or
several years. This discovery was made in
August, 1899. A continuation of his obser-
yations of the star has enabled him to de-
duce that the period OF the binary system
is 3 days % hours 14.3 minutes. Campbclls
conclusions riding this
Gently been confirmed in every particular
by DIR. J. Hartmann. at the Potsdam OBJ
servatory. Hartmalp's estimate OF the
period of the binary system differs from
Campbells by only three seconds.
The binary character of Capella was dis
covered independently by Professor Camp
bell at the Lick observatory, and by MIR. IL.
F. Newall. from observations made a; Cam
bridge, England In the case. OF this star
both components are luminous. They APP
pear to be about equal in mass ard not
very different in brightness Mr. Newall
has calculated that the radius of the orbit
is probably between 52.000.000 and 1o4 ,ooo.-
600 miles, or, say. somewhere between that
OF the orbit of Venus and that OF the
earth's. 1t seemed possible that under
favorable circumstances the components
would be far enough apart to be seen sep
arately with a telescope, and a series OF
observations made at Greenwich between
April and December of last year for the
purpose of testing this matter are reported
to have been successful. Although the two
compliments were nOt dCludll. StDdTalto
with the telescope, the disc OF the stars
image was seen Enthusiastically to be eion-
gated at those times when the eomponcnts
should, according to calculation, be the
farthest apart. Observations made at the
Lick observatory last summer with the
same object in view had, however, a diff
ferent result. Not the slightest elongation
of the stars disc could be detected, though
on at least one occasion the seeing" was
excellent.
The 10th of this month is the date for the
appearance of the meteors known as Orion
ids, their radiant-the point from which
they seem to shoot-being I'm the constella-
ton Orion. This system usually gives US
a fairly fine display. and 1t will be well to
bear the date in mind. The best of the dis
play occurs after midnight.
The "Demon" Star.
Minima Of the variable star Algol VIII
occur this month as follows: On the 9th at
midnight on the Sth at 0 pm. on the 18th
at IL pm. on the 3lst at p.m.-time given
to the nearest hour.
The Planets.
Mercury will be visible evening star
until near the close of the month. 1t will
be at its greatest brilliancy on the 10Th.
Look for it at low altitude south of west.
Venus is now fine evening star. al
though of only about one-third OF her bril-
liancy when at her brightest. On the 10th
of the month she viii be in conjunction
with Mars. Like Mercury, Venus is now
seen considerably south of west.
Mars is still evening star, but not
very brilliant. II is moving eastward.
During the month II win pass from Libra
into Scorpio. and at the end of the month
1t will be about six degrees northeast OF
Antares. setting at about Z pm.
Jupiter and Saturn are still conspicuous
evening stars in Sagittarius. Both are trav-
cling eastward. Jupiter faster than Saturn.
so that the interval between them is closing
up. Uranus in the Scorpion. ten degrees
northeast of Antares. Is also evening
star, setting about an hour before Jupiter.