Glacier County chief. [volume] (Browning, Mont.) 1931-1940, 1939-08-18
BILLINGS FATHER,
SON, STARGAZERS
DENIS H. O,BRIEN SR. AND JR.
HAVE BIG TELESCOPE IN
THEIR BACK YARD
After Four Years of Experimenting
They Now Use Instrument With g.
Inch Lense Which They Ground
Themselves.

Denis H. O'Brien, insurance
agent and director of the Billings
Municipal band, and his 19-year-
old son, Denis Jr., a sophomore in
mechanical engineering at Montana
State college, are fulLfledged
members of T. N. telescope nuts),
a term applied to the some 10000
"back yard astronomers" now ac-
tive in the United States.
After four years of experimenting
and work on different type telescopes,
the O'Briens now have a scope with
six-inch lens that is correct to mil
lionth OF an inch with which they
of their home. 1t took them IS hours
of actual work to grind the lens to
its present correctness. All work on the
telescope, from the lens to the five
foot tube, was done by the O'Briens,
elder and junior, because that is half
In addition to the IS hours of work
on the lens, there were many long
hours. but nevertheless interesting
hours. spent in testing the mirror. Pre-
cision instruments cannot measure the
lens, Senior OBrien says, but it must
be tested continually with light rays
It's a complicated process to the lay
man, but an appealing one to the
OBriens and the several other anna
teur astronomers in Billings.
Work Telescope Overtime
This summer the O'Brien telescope
has been working overtime, because OF
the nearnesS to the earth of the planet
Mars Each night astronomically mind
ed friends collect in the back yard and
have turns peering through the in
strument at the planet some 100000
miles away, the closest it has been to
the earth in the last Is years.
The telescope has been attached to
! temporary mount, but soon it Will
! be on an equatorial mount under con-
struction by the father and son, that
will move the scope to compensate with
the earth's rotation and thus keep
right on star that would otherwise
| flash out of the telescopes field. While
/ looking at Mars, the instrument has
! to be moved slowly, or the planet will
be lost from view as the earth TO
tates away from it.
ee n aadt t6e g 9B ths LARGE S5sh
boasts an R. F. T.. telescope, so calleo
because it views the sky on a wider
| angle and brings in a much larger
field of stars than the big tube. But
the siX-inch apparatus is the practical
one, and of the same size that has
!
coveries in astronomy. 1t is with this
| telescope that the T. Ms spend most
of their time these clear nights
The Altitude Helps
Montana is an excellent location for
astronomers, according to O'Brien ST.,
! because of the altitude, rarified air
and little smoke or fog. He knows of
a man back east, back yard aStron-
omer, vino was bitten by the bug and
spent some time and many dollars
! constructing a first-rate telescope. The
last O'Brien heard about him he had
been waiting four years to get clear
night SO he could put his Instrument
! into operation. The winter, because of
its clear nights, is the ideal time for
stargazing, but this summer has been
good. with but a few nights being
spoiled by smoke from forest fires.
The telescope cuts through some
smoke, but the haze makes the. planets
and stars indistinct. The O'Briens can
vary their scope from 81 to 24O power,
that is enlarging the diameters of any
body that much. Mars, which with the
naked eye looks like lantern hang
out to look like moon, or some
lockers say an orange. with a dark
spot visible in the center. At times the
ice cap, which tops the planet, is
thought visible through the instru-
ment.
Groundwork" Required
Astronomy is interesting work for
Denis and Denis. But before they ever
started grinding a lens they spent
hours studying the subject. 1t takes a
great deal of groundwork even to be
a T. N, they say. Now several high
school students have taken up the
hobby and soon some plan will prob
ably be made to form an amateur
astronomers club. There are many
scattered over the United States.
But it's not all stars and planets.
Once not long ago, the elder O,Brien
was catching up on his homework one
night, looking at the moon, when he
saw large bird fly across its surface,
then another until whole flock were
winging through the field on his tele-
scope. After a flustered minute, he
realized that he hadn't discovered any
moon birds" but rather that he was
viewing a flock of geese flying north
several thousand feet high.