Evening star., 1951-11-26
Scientists Watch Sun
For New Phenomenon
Reverse Of Sunspots Recorded
In Obscure Solar Flares
By Thomos R. Henry

In obscure Solar Flares
By Thomos R. Henry
A "sun patrol" soon may be thrown
around the world.
With newly devised automatons as
sentries, it's object will be to keep
24-hour watch for recently found and
still obscure phenomenon. the solar flare.
This is the reverse of sunspot. a
dark spot which appears on the suns
surface and which indicates cooler
region in the flaming gases. The fare
is an area of invisible brightness usually
quite close to a sunspot and of about
the same size. Such region obviously
is much hotter as the sunspot is much
cooler. than its surroundings.
From such spot comes an enormously
accentuated radiation of very short-wave
ultraviolet light, invisible to the human
eye. There also appears to be a radla-
ton of infinitesimally minute particles.
like electrons. There is, however. not
much, If any increase in visible light, so
that such an area cannot be detected
except with special instruments.
Sunspots Wax and Wane.
Sunspots have been studied intensively
for the past century. Their numbers
wax and wane over definite cycles OF
years They are believed to have con-
siderable effect on the earth's weather.
All sorts of other phenomena have been
associated with them, ranging from ami
NAL migrations to fluctuations OF the
stock market and the incidence OF wars.
There is reason to believe that these
ultra violet sunspots also produce con-
siderable effects on earth, especially on
radio transmission in the extreme upper
limits of the atmosphere. Some OF the
particles apparently are shot out with
such force that they traverse the SO ,000,-
900 miles of space between earth and
sun with almost the speed Of light.
There, as yet, is no evidence that they
recur in cycles.
The new instrument for observing
them has just been reported to the
American Association for the Advance
ment Of Science here by DR.. John w.
Evans of Harvard University's high alti-
tude observatory and the University Of
Colorado. 1t is a so-called bi-fringent
filter attached to telescope and an
automatically operating camera. The
visible light Of the sun is shut out The
other instruments with which only rough
results were possible.
One Station in Action.
One Of the new instruments has been
set up on Sacramento Peak, California
site Of the Harvard Observatory. This
has kept up a constant patrol Of the
sun since last March. Another is to
be set up at the University of Colorado
station at Climax, Colo. The work at
Sacramento Peak has been carried out
under auspices Of the research branch
of the Air Forces while the Office Of
Naval Research has had a similar role
at Climax. Another instrument for the
same type Of observations now Is being
constructed in Australia.
But from these three stations, DR..
Evans says. only very incomplete obser-
vations can be made Before the nature
and significance of the flares is thor
oughly understood it will be essential to
ring the globe with such instruments,
so that the whole solar disk can be
kept under observation throughout each
"a hours
The Sacramento Peak instrument runs
each day whenever the sun is free Of
tervals At the end Of the day the
film is processed and dries overnight.
The next morning it is examined for
flares. The position and area of each
one discovered are measured. the bright
ness estimated, and the minutes Of dis
covery. maximum brightness and end
ing are noted. The information imme-
diately is sent in coded telegram to
Noti 4f
Washington. where it is correlated with
various other data. Presumably the
same practice will be followed at other
stations.
For Radio Broadcasting.
1t now has been found, Dr. Evans
says that the flare areas serve as radio
broancaSting stations. One of them
emits 10000 times as much radio
noise" as comes from most similar areas
on the solar surface. Typical flares
have been found to appear suddenly
and rise to maximum brightness in a
few minutes. Then they die out gradu-
ally over period of about half hour.
Small flares are most numerous, and
the frequency decreases steadily with
increasing area.
1' piesehI udIe Is Delng oetecCeo
about once every eight hours. Their
frequency seems to follow roughly the
sunspot cycle, although it Is too early
TO say that they have any real cycle
of their own.
In a little more than six months
252 such flares have been recorded at
the Sacramento Peak station.