New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1883-02-08
FIG. L.-sTELLAR PARALLAX.


to be further off than the one we WISE to measure we e
get at the idea In the place ms TO the change OF
POSITION OF the earth If observe the star AT the point
T. when the earth at the upper and lower points Oh te
circle intended to represent It's orbit Its urectons "ou
be as indicated In the diagram. II observed from Iho
SUM- c. its direction would be again as ih"cd'eu' Ano
angle formed by these lines is the stars paalaK ts
the semi diameter Of the earths orbit seen at the star
inst as the paraav Of the planetary system Il inc si
diameter of the earth itself III we can ueuSuc ln'
angie shall have it all right Inc eiee' oil M up t,
lax would he 10 the II describe an orD he tn1
shown IN the lower eft-hand corner oI the ulhgla a.
thoug9 c@s ,.G"y vouT look ike circle; if edge
wise, the apparent orbit would be straight NM ~.
besides that star has proper motion. then the result
Wi, he tbat i'm the coursc of year will appear To de
scribe u path like the loops in the diagram Wen; nov,
what star shall try parnlax on ht7t We h'''ra,:y
ny r " ,ho 90 ttci Rut how about star that drifts
fast in the SKIS What does that meant II 'st rHi
tbat il l. nrtty near Us Certainly, II near us us ullt
viii be ra1id So Bes.e said: We must try those stars
that ting most rapidly ana thai M q
most convenient 10 measure from" The little STAR no
II Cvgi was whisking along more rapidly thai Others
with reference fo IT, What lac dd 10 measure every
day o the year with his micrometer the distance rom
u 4 md from 4. and hc kept up lho,' ih'''.i'
Incnt, for something like three years aud on computing
MI. yorpl,tiu, tine w0r-hc found That the star was
moving I'm the path described; tha H. III nIuVn ~
made M OF driit straight ahead plus motion OF tha
kind The distance between the ends oi the star "I3
he found IL about tWo-thIdS SccoLu o. mr. ."c
paraax being little more than one rl sec"'1 q" al
You will notice that that assumes however, u'l i
two star, have no paridN az au NHal you e.. ia. ,i
way j. merely thr difference between the pardhX OF inns
auA the nelghhnrng More recent ihNcsugl'i''s
have MP the number that he gave 10 about one ii!
second OF are. the length OF This orbit beng c1; ano
and the that star has been repeated, over mn
over again. al least hall dozen llint'' nn' ~ MI
does that meant Onc-hat second Oh ar, means ,'
star Is 100000 times far away 20, the distance rom
the ea IN 10 the sun Nou remember That story about
our SLoooooo railroad fare To tie sun You t'H'
luOuoO uu's thal I'D oIcI l." i.''l lO -, IN, I'm,
II would take tho Hight about seven years 10 come l"n
that star 20 the Garth and We ma maj oA ln' "Ao '
most convenient way TO eXpir'' me "l,'HHt'; ,,,
The very net wear after this was published indeed
star Alpha tCutaui n Tie southern lirh,-' wa
ycstI2atcd Icy Henderson "a the Cape 81 """d lioe Hha
lie found that that STAR which il dr tins along at
The rate OF about four and half seconds year; was
Therefore about oue-ili The distance taxing hh''
three aud half years for - light to travel 4" me cartn
That f. far known, our nearest ucighhor among
Ine N'u stars. Hn s rr2J lst Star further
OIL Mr. Elkms's careful Investigations seemed 70 show
that that IurgN g. too lii-r ANA pIoNhht iAr phIih
81 Alpha Ceutuui is not much greater than thai oi o
,',, 80 now ", ,i t,,"t Tho sii cct need. To-
De- invest gated. nuI viii br very speedy by tIt Lr"
series OF ou-crs atoms u the Southern Hemisphere
DISTANCES or STARS NEAsUurp BY YEARS.
Now / cauuot spend time % sifr you great dear
nou the painlaN OF rho STAR except Co say Tint Their"
are something like twenty 20 twenty five 20 Doe meas
ur.d. nearest ncish3or. Alpha CcniaurL j. bright
of the first uaruituic, ana very me one i''
one Of the hrlchtct in tuc sky Tac next one 40 ai az
we know e. dl Cycui which s visible 90 the mixed eye
utt. sixth magnitude stIr Next 20 That comes so
2Il.5 Of Ialandc cataoroa little star of the seventh
ma ,rtudc giving only about ouc-hii much light ns
the other The nc Lhor is Beta Cc1'aIL another
stur nearly nt-hf IA Alpha 'rnihlfl: hht iini j.
about seven wear, AWAY and ~ little Then There is
q tlr star iu Cus-i"pctN Nj tn~-loptur SIMON alI'T7
am very doubtful. however about tn, ono oi % ma
been observed hu One" iy one ob,er'cr. ih'n come.
sf.. tffI' r.
a,s'.n1 "i M, ,r I'tcr star f. 30 ei.5o o. la
indc- catiogue which appears 10 have di-inno6 Of
1,c f tiric,i yeaf- Then wee CONC 10 fue two great
f,r siri. fhr brcLtc-t ~ n fixed stars, aud the
~, IN Instant fr,n the Garth with parallnN 81
mont ,n.. nffb second A. to Alpha IyfI.. There
little doubt hlt 10 j. correct the Inst lu''ru.uii"n OF
pro-or nan ~ Washington agreeing very CLOSELY with
are more di.rordsut Some would put ii u- u'lr 90,
fourteen ycnr- aud othcrs ~ far away ms iTcni three
wears Tho Wild star. 80 I,-3O GrOomhrd-e, appears
10 bc th!rt forty lcnra AWAY ana NJ" Win Ai'lu-
rus which f. about tr same distance. ou ,"r that we
are inst al orr wits end measuring IA distances ~
the stars We deal pretty Wei with TIE pdHlaA oi
a " hole .econd. OF half second end thc probable
error vs. NOT DE di- ,rnccln-thu H. not over fourth Of
the whole. But when You come To measure one -itHlh
error. Of your Instrument. thu result viii Doe doubt
ul. wien -hy the d-ihnr" "i n' I0' -tri i' come
forty years, MN simply sh}'hE lhnt tt l7 Whit the
observations indicate. But IL !- very certain t.nt the
discrepancy wiI Doe s"mcNht between -"'V years ana
ha .e doubt that thr neat century WIZ .'r such
improvements IN facilities that wc shall Doe ahl" 10
cauy measui'mcnt- very nuch "Ilnrt man We can
al present Bat VIII say 90 thi, point That 60 not
think that the material We hav" wtrrnt- very c1i"n-
sSe succulutOu- On the cou-ii ucuou 81" th' universe ia
muttrr, OF thu Kind. winch have Tor ih'it N'IJ iouu
dution knowledge OF The distances OF thr stars
Now wien We know the distances of the star We can
then quite easily determine their real brightness. We
nnd thai the brighter stars can h con pared WIN ihe ln
with some degree "i "c 'oI 'u q 1 ",
OF the star sirius. % would take about .oopoOoouO Oi
them to make hsht as "utnl ~ s"H.-A' IN IT,
Iva, would take about from il0ou.o0pOoo 10 $4,000,
600 900 according 90 L,uc, results ana little star of
tie sixth magnitude would th' luo Uiu'7 NJ many lo
make -iull- bright - the sun II Womb take
Nov talIug into account their distances, We md ana
yoa WI -cr - iustihr7 NY statement c"''I!lnk ,h'h
as bright TIE acco rIng ~ we TAKE the phi"aN
of one fourth cghtc' hnn"Ich'i- oI He'" "I HIc
ANAL The star Alpha Lyi@ tomcs out some "h enc uc-
tWcau twenty five and thirty times a, Iu hlou7 ns l'
bright ~ The -l.' hu, lI' ,' % S" tyi,i't ~,
bright ~ the sun Herr IT, rang Hu"nS 80 , ,i
dozen stars Of nearly Loo 10 j. 20 'Hi "' ANo" 'N')
ya., 10 te next diagram now Of doub' STARS for We
o h.r we r, ol.cryiug liar, that very frequently
have pairs star. Very lew OF these can be- seen ny
, cauricorni yhich can be- seen a. stiurtly
separate by very sharp eye while with the telescope
we lind broken no into two pair, ot -thr-. Win mum
hcr Of itlc one, betwrrn them Now az the time of
Hcrschc 100 OF these pairs Of stars had been noticed
erSchc took the subject. thin ung hc woud get al
the suns parb,x by measuring the distance of star
from nnotlcr The real tina, they great
distance apart Like Jacob he went To- hunt hi~ fathers
comuar -on that these stur- were gong around each
other The first star that he noted wac the star ANNA
Vrgiuls when 10 was frat observed n, direction
entirely different from what it appeared 10 be later
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