The times. [volume] (Richmond, Va.) 1890-1903, 1890-04-05
THE APRIL HEAVENS.


/ t""A tht comlnnents OF many were mOYin|
through space with The same velocity am,
I DID tnc same direction. Such a movement
would certainly indicate that they had som,
bond Of union. For what are the chance
OF these stars haNln. the same velocity hl
aecidonif \ little later hy studying hr
/ observations more carefully. 10 was fOuut
that one star actually rc'olYed about IN,
other in an oval orbit. Since then man,
double stars have been seen % make Ou,
/ entire revolution. SO that &c is now proved
/ beyond AN doubt that there are system.
/ which consist % more than one sun.
AZ first sight 10 might seem very easy O.
ascertain this period by simply watching
the componcnte until they have made one
revolution. Tn The great majority Of cases
I however 10 would require many liletmes OF
patient watching before hepefi0d could D.,
ascCrisined. Most people like 20 get some
immediate result from ihcir work. Hence
mathematics is res0ried 20. When the di-
mansions of an orbit are known and
| the star has been followed COM
paraiNciy short time, the period of
revolution can be computed. A period
found uu this way, however, is not
/ thoroughly trustworthy ON account of the
uncertainty of the observations. When We
recall the fact that these stars appear so
close together that 20 anything bat tele-
scope the great majority NJ them look like
single stars, 20 il easy O. realize the difi-
Guilty of making accurate observations.
I The angle which the two cOmpOnenis of
Castor. a bright star in tbe constellation OF
/ The Twins. subteud is the same that stick,
one inch long, would if ii were one mile oil.
/ That is, the two stars appear as far apart as
two dots. am iuchaapart. would 70 they were
mile away. The orbit described 10y the
TWO comu0uenls OF /eta Oancri might De
represented nl "a penny. a mile from us,
ln This case. we are not looking strai ght
upon the orbit. bat very much from one side.
so that the penny should DE turned % give
ihe appearance Of very narrow oval.
These TWO stars take about go years TO make
one evolution. There is a third star, little
way from these, that moves in tnc same de
rectiOn and reyolycs around the first two in
five hundred years. lfone looks at Vega, the
highest star i'm the constellation of lyTa. one
viii See toward the west two fiih-magni-
tudc stars That form, tOgcthcrWit Vega. am
tQuilaieral triangle. Zach side Of the tri-
angie is about four diametcrs of the moon.
One ei the faint stars i- double. and the two
component, can easily DE distinguished by
the naked eye. Which star is double we
will leave for each observer 90 find ont for
hims0i 10. for the object is rather "a good test
tests. such as the number Of stars
one can see in the pleIades. show
only The penetrating power Of the
eve. Whom this double star is eXam-
incd through telescope each component is
found tO Dee nits turn double star. Each
pair has period of about two hundred
years, while the pairs reNOlNe around some
common centre OF attraction iu many mill
lions of years. One OF the most beautiful
double stars is Beta Cyeni. The larger
STAR oi the third magnitude Us Of a bright
L .HrI'.|.m IlI.rr |i'| fNI NHfHN.H ID fIl
seventh magnitude, is green or blue.
There is very curious relation between
/ the c0iors OF q double star that is not at all
understood. and. in fact. 10 is doubted by
some whether itcXists or mott 10 is that the
cOlOrs OF the secondary star is further to-
ward the violet end off ohe spectrum than
/ That 0f the principal STAR Accordingly. if
tine brighter is red or yellow. the fainter star
viii Dee green or blue
/ A very interesting discovery NJ q double
star has lately been made at The Cambridge
/ Observatory ny means of tine spectr0scoue.
/ The lines in the spectrum OF certain star
are found t0 vary boo width. NOW let us see
/ h0w the observation OF such fact can lead
I tO the discovery of double STAR II ile
plane of the orbit Of "a double star lies very
nearly bon the lime Of -igli-ihat is. 10
/ the penny above referred 10 appears 20
/ us as "a straight iine-Oue OF the comp0neni-
would Dee approaching us while ,nc other ie
reccdng. Bv laws given Don the last article
+ the lines in the spectrum Of the former would
move toward ine violet and those iu the spe
trum of ihe latter toward tle red. Vow ii
] these are so lir IN Chat even through iele-
/ scope llnf appear as single star, The spec
tum. oi course. would have only one set of
lines. But these dark bands would tend io
widsu or marrow periodically as first ONE stan
and then another Dis approaching or rectding
IAe period u.s. very uncertain ON account o..
lle difficulty of measuring such extremely
minute quantities.
10 would Dee interesting ii ly some SINH
lar method we could discover ile cause of
variable stars. especially those Of the Aie)l
glass. AS explained 100 The article for lasi
duly. yAriahie- Oi this class remain iOrdays
perfectly constant in brightness. then. boo O.
few hours they VIII decrease io the magni
tude of a comparatively faint star and re-
turn again Oh their former hrlIiucy. the
almost perfect regularity of These Stars
makes it possible for their variability To- De
due 90 % dark planet revolving around
ine star aud once in every revolution
mtercepling part Of the light. Some of
these yarIlbe- grow so excessively faint
that either the planet must De great way
from Tie star or very large and near ln
many stnrs. however. we have another cOn-
diii0n. that the period les very short. Hence
with such stars Che planet must. in all prob
ability, Doe near the primary For even ibc
small orbit BE- would then have would re-
Uire "a velocity unknown iu the solar sy3-
tenn. Another interesting example OF a
/ double stan. when one NJ the cOmp0neuls
is almost u0n-umnous. is Sirius. For
come time 10 bad been noticed that Sirius
did NOT move in 90 perfectly straight lime
/ through space bdt had "a slight WarDllu-
motion. lf Was suspected that irregular
tiles were caused by the attraction of O
companion. which. as 10 reNoNcd around
Sirius. pulled DO first tO one side and then 90
the other. The orbit and period 90 ths
invisible star were computed. sO that one
could predict for any given time where ID
would Dee. When Mr.. Aiyan Clark was
. testing DIS new 3-inch telescope hc found
this companion in exactly the place II was
supposed Oh occupy.
Can life. as 10 is known i0 us. exist in
/ such systems a- theses II 10 does, what re-
markable phenomena the inhabitants Wit
ness. firl. "a red sun might rise, cross their
F heavens and set. Then. without giving them
/ time for sleep, yellow SUR, accompanied by
T % green or blue attendant, would appear.
I We can picture 90 ourselves indefinitely .c
I wonderful effect these cOlOrs would have on
/ the lDlaeea and atmosphere. w ben Wc think,
/ however. Of the tremendous changes in tem-
u.rntnre. such a planet would under
/ eo. where SD many suns are coniending
/ Tor JOS possession, We are compelled 90
conclude that Che question musthaYe neg
IatIye answer. And yet we must not Dee
T too hlsiy iu taking The next stop-thai liic.
then. does rot exist There at all For ii
would Doe perfectly possible Chat there may
/ De beings superior 90 ourselves and yet en-
tirely different. I'm fact, If life Is am element
of the universe. as perhaps matter ana mo-
ton are. then would 10 NOT adapt itself o. It's
surroundings. Dec them De- what they may
such certainly would Dee the case II The De-
Z lief of tine Brahmius De- true.
The NlrlaDie-, given to those VINO ic-
spouded % the appeal for more Observers Oh
I such stars. have now become difficult 10 op-
-erge owing o. their position. 10 the OBJ
server. will send mo their original oDsefNa-
/ lions. shall be glad io reduce them, and %
/ the results are trustworthy, publish them.
/ Address $50 Thaycr Hall, Harvard Oniyer-
sity. Cambridge Mass.
Venus is evening star this month. II sets