The New York herald., 1922-12-31


The lines are greatly influenced by
temperature and widened by pressure,
and Adams at Mount Wilson Observatory
has found the temperatures OF many
stars from the study Of spectral lines.
Given the temperature 1t Is a simple
matter to compute the actual bright
ness and therefore the distance of the
star.
In closing DR.. Mitchell said THE
past decade has witnessed remarkable
increase Of knowledge in all departments
OF sdereal astronomy. Progress for the
future viii depend, as 1t has always de-
pended in the past. ON securing the OBJ
servational date with as high degree
OF precision as possible. The most i'm
portant link in the chain of progress
for perfectins our ideas of the system
of the stars seems still to lie in the accu-
rate determination Of stellar distance
A second paper, by Rufus Sawyer and
DIR. Patton OF the University OF Michigan,
showed that a number OF hitherto un-
explained lines in the spectra of white
and blue stars can be attributed to the
element silicon. a paper of Luyten and
Landmark showed how the distances
and absolute magnitude of stars might
be estimated from study of their spec
tral type. especially IL we can measure
previously their motion on the face Of
the sky.
One of the interesting results, al
though little weight should be attached
to It for the data are extremely uncer-
tain showed that the bright star, Deneb,
Is hundred thousand times as bright
as our sun. Ii true. this will mean
that it is as brilliant star as has
ever been observed and although this
is not probable. the fact remains that
certainly it is a very bright star.
DR.. Henry Norris Russell of Prince
ton gave n very important paper deal
ing with the masses and distances of
the stars. For some time he has been
working on the problem and now has
tabulated the distances of some sixteen
hundred stars To solve the problem he
used the measures of many double stars
that are actually moving around each
other.
The stars revolve about each other
in an elliptical path and If the star
has been observed through the entire
distance the problem is easy. How
ever. as Dr. Russell stated. there are
many stars which have a period of rev.
olution OF several hundred years and
being slightly impatient he devised
method of using the existing data
without waiting for complete orbit
Some years ago DIR. Russell showed
that the history of a star was not very
complicated. A huge mass of gas in
space would contract under it's own force
of gravity and the increased pressure
due to its smaller size would cause a
rise in temperature until the star
reached a certain point where 1t was so
hot and dense that further compression
was difficult. AT this point the star
| would begin to cool and finally reach
oblivion. The more matter the star
contains the greater is the force OF
gravity at it's surface. causing the tenn
perature to rise still further DR.. Rus
sells results clearly indicated that the
hotter stars were more massive.
! Greatest Puzzle Discussed.
Another important paper from Mount
Wilson Observatory by DR.. Joy dealt
with the greatest puzzle that is known
to astronomers. AS yet they have been
able TO find no theory to account for the
fact that certain stars fade out and then
grow brighter at more or less regular
intervals usually about year. The
star Omicron Ceti in that time varies
it's brightness more than a thousand
times. DIR. Joy has analyZed the light
! from the star when at minimum. and
has shown that some effects can be ex-
! planned. There is a second star revolv-