Knoxville journal. [volume] (Knoxville, Iowa) 1874-1986, 1875-07-22
Variable and Fixed Stars.

Variable and Fixed Stars.
We talk of the fixed" stars, and to the
common eye there seems no more appro-
PIRATE type of immutability and immobil-
ity than the steadfast orbs that look down
upon US as they did on the Chaldean as
trologers 1000 years ago, grouped in the
same consultations, and shining individ.
ually with the same degree of brightness
as in that OZARK, backward and abysm OF
time" One star tliffereth from another
star in glory, but So IL has been since they
first sang together at the dawn of creation.
It il not easy for us To think of any change
in their relative rank from age 10 age, or
in their number or their appointed stations
in the heavens,
And yet, when we cease to watch them
more attentiyely, we find that, SO tar from
being fixedr and unchanging, the starry
heavens are the theater OF incessant mo-
| ton and continuous transformation. The
| armament, the very name OF which inn
| plies tiXedness, is full of activity and mo-
bility. II is not liieless, crystallized, inor-
ganic, but living, ever-changing organ.
| ism. Its movements are as manifold and
as complex as those going on in an animal
| body, with all its processes of nutrition,
| circulation, growth and repair, Let us
| take single one of these forms of activity
as an illustration-say the phenomena OF
variable stars
Among the stars in the northern quarter
| of the heavens, almost continually above
| the horizon in our latitude, Is one of the
second magnitude in the constellation
Perseus commonly known by its old
Arabic name Of Algol. II Is not easy to
define its position without diagram, but
the reader. If not already familiar with IT,
can readily find IL with the aid of the star
maps in an elementary or popular manual
Of astronomy. Having once become &C.
auanted with II he might look at 1t again
| and again without observing anything to
distinguish il from IT. celestial compan-
| ions. But if he seeks it night after night
| the time will come when il will appear TO
| be missing from its accustomed post. Its
! bright neighbors will all be there but Al
| gol will seem To have vanished for one
who is not infinitely familiar with the
heavens will not be likely to notice that Il
| faint star of the fourth magnitude IL glim.
mering in its place. That faint star Is
Algol, temporarily shorn of his splendor,
and if you look again few hours later
you will find him blazing with his former
brilliancy To he more precise, the star
is of the second magnitude (as bright as
the stars In 1.-The Dipper'0 for two days,
| thirteen and halfhours, then IL suddenly
| decreases, and In three and q half hours
| has faded 10 the fourth magnitude; IL re.
main. thus onlyabout twenty minutes, and
| in less than four hours more has regained
its full brightness, to go through the same
cycle OF changes again. The exact period
| in which the variations are completed Is
| two days, twenty hours, forty-nine min.
utes As the star Is at full brilliancy for
more than two days and half out Of this
period of less than three days, one may,
as we have intimated, look at II a great
many times without suspecting that 1t Is
variable.
The new or g temporary" stars that have
now and then appeared in the heavens,
blazed for time, and then been apparent.
ly extinguished, may perhaps be . yaria.
bles' of long period The first Of these on
record was observed by Hipparchus 1875
years before the Christian era, and Is said
10 have led him to make the star-cata-
logue bearing his name. There was
another remarkable one In A. ID. 3s3,
which for three weeks riyaled the splen-
dor OF Venus, then vanished, and has
never since been seen. In 1872 star sud.
denly blazed out in the constellation OF
Cassiopeia. When first observed il was as
| bright as Sirius, and II increased In
| radiance until it could be seen at mid.
day. A month later ii had begun TO
wane, and in sixteen months II was en-
| tirely lost 10 view. This star was very
carefully observed by Tycho Brahe, and
IL was nnquestionably star, and not u
comet AS temporary stars had been seen
| in nearly the same position IN o4o ana
| 1894 Il has been thought not impossible
| that all three might be the temperance
Of the same variable star, having mean
period Of about 315 years. II so, ITS next
maximum would occur not far from 1900.
| Other extraordinary stars have made
| their appearance since that OF 1917, Two Of
them within a few years, one in Ophiu'
| cliis in ls4s, and the other in Corona IN
| 1865 The latter was seen Of the second
magnitude May i2, and diminished to
the ninth by June .. Is spectrum was
examined, and was unlike that OF any
other celestial body. II was compound,
and indicated an incandescent body, sur
rounded by a luminous gas consisting
chiefly Of hydrogen. II was suggested 10
| explanation Of these phenomena that some
vast CONFUSION had caused great out
| burst Of gas from the star, and that The
| hydrogen in this gas burned and heated 70
vivid incandesceDce the solid matter OF the
| atmosphere.
The phenomena Of variable stars, ike
Algol and Mira, must be accounted Tor In
different way, and various theories have
been suggested. no one Of which ~ perfectly
satisfactory Some have thought that the
! observation Is caused by q dark, opaque