The Providence news. (Providence [R.I.]) 1891-1906, 1899-10-09
POLE STARS
TWIN DEFINED,
Though Unseen Il Makes a
Revolution Every Three Days.
=
THERE MAY Be ATHIRD MEMBER
Polarls and Mate Move Toward Earth at
Rate Of 777,60 Miles a Day.
THERE is NO DANGER OF COLLISION.
Phenomena Discovered Recently BY Prof. Campbell
Of Lick Observatory and COniIms1 BY Prof.
Frost Of Tho Ysrkss Observatory.

Williams Bay. Wis. oct. 9.--It Is now
proved beyond the shadow OF a doubt
that the familiar pole star, known to
astronomers as Polaris. is i'm reality a
double star. To be more exact. the POI
lar star. which we see. has a compan-
iof. which is unseen. and the two re-
Volve about each other. or rather about
common center of gravity. as the two
balls of "A dumb bell might revOlve IL
suspended by the connecting bar.
The theory of a composite system OF
Polaris was first advanced by Prof. w.
w Campbell OF the Lick observatory
a few weeks ago. and has since been
confirmed by Prof. Edwin II. Frost of
the Yerl<es observatory. located here,
whose observations and measurements
tally almost exactly with those made
by Prof. Campbell.
The latter gentleman Is OF the opin-
ion that There Is third member. also
dark. TO this system. This. Prof Frost
says. Is possible. but cannot be ascer-
tained EXCEPT by series Of observa-
tions covering period OF two or three
years.
MOVING TOWARD THIS PLANET.
Polaris and it's unseen companion
make a complete revolution i'm three
days. Both together. or the three II
there be three. are moving toward the
earth with a velocity of nine miles per
second. $40 miles a minutes. 81. 400 miles
an hour. 177600 miles day, 2S3, ,s24 900
miles "A wear.
Though coming at such an incredible
rate Of speed. there is no danger that
i'm the immediate future Polaris will
inn
In fact. there has been no appreciable
difference in the appearance OF the star
i'm spite OF its ra pid approach, during
the last one thousand years
The method bv which Prof. Frost ar
rived at his conclusions was not by
looking through the Yerkes telescope.
for the most powerful instrument could
not determine ANYTHING definitely nor
cam an instrument be made that could
render the movements of this double
star visible to the eve.
II IL the spectrdscope which reveals
these secrets to the scientist II is with
the speCtroscope that astronomers are
adding TO their store OF knowledge
facts which the telescope unaided could
never reveal. Astronomers are Just
awakening to the vast importance ~
this instrument. and there are but
three ef foHr i'm existence that are cap
able of detecting the double nature IL
we may so term it, OF the pole star(D
WORK OF THE sPECTRoScoPE.
The spectroscoDe is an elabo-
rate form Of prism which sepa-
rates the rays Of light into their prl-
mary colors. This is called the spec-
trum. The rainbow is the spectrum
OF the sun. The spectrum. when shown
distinctly. is crossed by numbers of fine
vertical lines which vary according TO
the substance producing the light. This
has long been recognized as an infal-
lible means of determining the sub
stances Of which the heavenly bodies
are Composed.
II is but latelv that the spectrum
was found to reveal motion But N is |
only motion toward and away from the !
observer that can he detected When |
the light giving body is moving toward |
the observer the waves of light come |
with greater rapidity, causing the blue |
portion of the spectrum to become |
more pronounced and the fine lines are /
shifted toward the blue
When the body moves i'm an opposite |
direction the waves of light come with |
less rapidity and the opposite result is |
noticed In "A series of observations the |
distance and velocity of motion cam be |
determined accurately by the shifting 1
Of these lines on the spectrum. The |
speCtIoscope Is Pt+4e-Aeel ite the big tele-
scope. The spectrum OF the star as /
msgr'fed hv the telescope Is thus oh
tained. This spectrum is photograph
cd. The photoera phic plates are placed /
under micrometer and the shifting OF |
the lines is measured.