The Indianapolis times. [volume] (Indianapolis [Ind.]) 1922-1965, 1935-01-16
Today S Science
by DAVID DIETZ-

A STRONOMERS may soon have TO revise their
N estimates of the temperatures of the stars:
The necessity for this seems likely as the result Oh
researches now being carried on at the Yerkes Oo
servatory under the direction OF Dr. Wlllam W.
Morgan with new types of apparatus and hyper
sensitive Photographic plates.
Present estimates give our own sun, which Is
yellow or Type G star, a surface temperature Oh
SOM erees centigrade or 10000 degrees Fahrenheit
The coolest known stars the red giants such as the
star Mira are estimated to have surface tempera-
t1Ire of 1900 degrees centigrade or 300 degrees
Fahrenheit The hottest stars, the olue-Whlte stars
are believed to have surface temperature OF $1,000
degrees centigrade or 10000 degrees Fahrenheit.
That these figures should be coming in for rev1-
sion this time should surprise no one LOT the laSC
year has been one during which many reViSloflS nave
been made in our notions about the heavens care
full observations with instruments as well as the
development of theories have neceSSltated many
changes in the astronomical picture
OUNCE the sun is % million miles away, ard the
- nearest star 25 trillion miles away, it is OBVIOUS
that there direct way of measuring stellar Tenn
peratures.
The temperature of star has been arrived at
IN the mast bv the application of what is known as
Plancks law. This law. formulated by the famous
physicist DR. Max Planck states that as temperature
goes up the maximum peak of energy moves
forward from the red end of the spectrum toward
the violet. A fairly hot star is red hot very hot
one is white hot.
Consequently. the method of calculating the tenn
: spectrum and then to determine where the energy
peak occurred in the spectrum. Plancks law was
then applied.
But DR. Morgan has been using representative
mates which record infra-red light, rays which are
invisible to the eye. These plates incidentally, are
extremely difficult to work with Because of their
extreme sensitivty to heat. they must be kept
chilled for they dsintegrate at ordinary room tenn
peratlres.
With the aid Of these plates. DR.. Morgan and
his associates Prof. B. A Wooten of the University
of Alabama and Richard F. Kinnaird of the Yerkes
staff have found that some stars emit twice
three times as much infra-red light as could be ex
pected upon the basis of Planck's law.
lust what this means. remains TO be explained,
j according 10 DR.. Otto Strive, director of the
Yerkes Observatory.
In the case of some stars" he says, sit may be
due to ABSORPTION in dust clouds in interStellar
space These dust clouds acting they do in
our own atmosphere. as in the case of sunsets and
are making the stars look redder than they are"
In other words this would mean that past
measurements of the energy distribution of the light
Of these stars would be wrong due to the greater
absorption of energy at the higher frequencies
But this explanation is not true for all stars"
Or. Strive adds and it is quite probable that in
some Of them Planck's law may not properly be
used Dr. Morgsn's findings indicate that there is
considerable doubt in regard to all stellar tempera
lures derived from the application Of Plancks law"