Evening star. [volume] (Washington, D.C.) 1854-1972, 1954-12-15
Man Can Measure
Tiny Port Of Universe
Carnegie Experts Mapping
Scale of Visible Creation
By THONGS r. Henry


About one per cent Of the universe
now can be measured"
! This is the relatively small area Of
space within a few million light years
Ia light year is the distance light
travels IN year at speed of 10000
miles second-of the Milky Way
galaxy Of which the earth is part.
The other 80 per cent. with mil
lions of billion-star galaxies scattered
through the far reaches of creation.
still defies direct measurement and its
distances and properties. must be de-
duced.
Such is the report by astronomers Of
the Carnegie Institution Of Washing
ton on progress of the program Of
mapping the universe which started
with the opening of the 2o0-inch Mount
Palomar telescope late in 1949.
Before this, only the so-called local
group" Of seven galaxies. at least two
OF which are as large as the Milky
Way system. were within reach of di-
rect telescope observation. The most
distant was hardly more than q million
light years from the earth.
Light variation Is hey.
Within this local group 1t was pos
sible to detect two types of stars-nova
and the so-called cepheid variables
which are good distance indicators.
The latter are very massive stars whose
brightness varies periodically like flick
ering candles. The brighter the star,
the greater the period. When the light
pulsates every day. 1t had previously
been established, the star is 100 times
as bright as the sun. When the period
Is 10 days. the star Is 1000 times as
bright as the sun.
Knowing the absolute brightness Of
the star, it was possible to calculate it's
distance from its apparent brightness
as observed through telescope.
The other type of measuring object,
was the nova, star which suddenly
flares up to several thousand times its
ordinary brightness and then declines
to its former state after few days.
New stars" could be detected in the
other galaxies of the local group and
compared with those known for many
years in the Milky Way system.
Titan of Creation Found.
The 200-inch, according to the report
of DR.. Ira S. Bowen. director of the
Mount Palomar and Mount Wilson
observatorieS, has made it possible to
extend such observations to a titan of
creation lying far beyond the remotest
member of the local group. It consists
OF nine certain galaxieS, each probably
containing billions of stars, which have
been known for some years, and seven
smaller-at least fainter oneS-found
this year. 1t lies at the greatest dis
lance which the sky surveyors can
reach with their established yardsticks.
Within these galaxies to date have
been distinguished 10 cepheids with
pulSation periods of from 10 to 81 DAYS.
and % normal nova. BY means of
these, fairly accurate distances can be
determined. Then the brightness of
objects at such distances can be COM
pared, with new and highly compli-
Gated technique which avoids some of
the errors of the past, with that of
Similar objects at greater distances.
The astronomers are trying to eStab-
fish the validity of the red shift" as
a measure of galactic distances. These
great star systems appear to be reced-
ing from the observer at speeds which
increase with distance 300 miles
per second per million light years.
Among the objects distinguished dur
ing the year, two are reported with
velocities Of recession exceeding 1000
kilometers second. Their light must
have started towards the earth more
than Is million years ago.