Evening star., 1935-04-22
BY THOMAS r. HENRY.

Laboring night after night for six
years on a starlit Virginia mountain
top, two astronomers have obtained
independent proof Of the 100000, ,000-
year rotation of the 10000. 900 600
star Milky Way galaxy Of which the
solar system is single unit.
These astronomers. Drs. Piet Van
de Kamp and Alexander N. Vyssotsky
Of the University Of Virginia. re-
ported their findings at the annual
meeting of the National Academy Of
Sciences here today. The six-year
study was conducted at the Nc
Cormick Observatory on top of
Mount Jefferson near Charlottesville
and involved more than $4,000 ex-
tremely precise measurements Of the
motions of some of the faintest stars
observable by man.
They photographed 34l small Sc
iected areas. Altogether, they re-
ported, their observations cover about
half of l per cent of the observable
heavens. It has been known for
some years that. judging from the
1dl 6Cl oAlo b116ltCl otd1 GLAC SACot
galaxy appears to be rotating around
some fixed central point in the con-
stellation Of the Scorpion and that
the earth and sun are taking part
in this celestial journey lasting ap-
proximately 200,000,000 years. There
has always been the question, how
ever, as to whether the bright stars
which are comparatively few in num-
Der might not constitute q system
with a rotary motion of its own In
which the galaxy as a whole did not
take part. BY far the greater num-
Der of the stellar bodies making up
the galaxy are faint stars, invisible
with the naked eye. The sun probably
represents a fair average.
The two Virginia astronomers made
their Photographic measurements with
stars ranging from the seventh to the
fourteenth magnitude. A star Of the
first magnitude is one which is barely
visible without effort to the ordinary
naked eye. Magnitude increases as
the stars become fainter and fainter
so that star Of the seventh magni-
tude would be very far below the
limits of unaided human vision.
Measurements of the motions Of
these $4,000 stars showed that they
are sharing, in general, the rotary
motion Of the very luminous stellar
bodies. thus confirming the thesis of
the celestial year which lasts for 200,-
100000 solar years. They found that
the shearing effect of the stellar
orbits around the distant center Of
the galactic centering around the
Milky Way and including all the stars
in the visible heavens turns out to be
practically identical with the values
obtained for bright stars. The meas
urements also confirm the location of
the center In the constellation Of the
Scorpion.
In addition to the results obtained
in the study of galactic rotations, the
two astronomers made measurements
which gave valuable data on the suns
motion, procession, absorption Of light
in space, and star streaming. The
effect Of star streaming Is found well
pronounced among faint stars.
Bright Stars Show Deviation.
According to the theory of rotation
Of the galaxy, the position of the
vertex, or direction of the greatest
motion among the stars, should COIN
eide with the direction to the center
of the galaxy. This is found to be
true for the absolutely faint stars. At
the same time it was found that the
bright or massive giant stars show q
marked deviation from the position of
the vertex. This fact, they point out,
may have an important bearing on