1944-Note_on_the_Discovery_of_Red_Stars-Haro.pdf

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VOL.
30,
1944
ASTRONOMY:
G.
HARO
AV
247
The
formula
predicts
that when p
=
2.105
-
will be
approximately
0.514;
when
p
=
106
-
will
be
approximately
0.752.
To compress Li to a
density
ten
times its original density,
a
pressure
of
around
6.5 X
106
atmospheres
is
necessary.
In
conclusion
we add
the
remark that when
the pressure is small
enough
so
that its
influence
upon the elastic
constants is
negligible
the
appropriate
formula
is
*
Av~~~~~~~~v
V°=g/C;~v
v
I&V=
VO
-P/C
ADDED IN
PROOF.
It
is worthy
of
attention
that the formula
given
here
is, when the
dimensionless
constant
ck is
assigned
the value 2,
precisely
that
which
leads
to
Laplace's
well known law
of
density distribution
throughout the
interior
of
the eaxth.
This
law fits the observed facts re-
markably
well
but
it
has
been
regarded
by
many
authorities
as
merely
empirical
largely because
its
connection
with
the law of
compressibility
has
not
been clearly
presented.
1
"Finite
Deformations
of an
Elastic
Solid,"
Amer.
Jour.
Math.,
59,
235-260 (1937).
2
"The
Compressibility
of
Solids,"
von
Kdrm4n
Anniversary
Volume,
1941, pp. 121-136.
3
"Compressions
and
Polymorphic
Transitions of
Seventeen
Elements
to
105
Kg./-
Cm.2,"
Phys.
Rev.,
60,
351-354
(1941).
NOTE
ON
THE
DISCO
VERY
OF
RED
STARS
BY
GUILLERMO
HARo
HARVARD
COLLEGE
OBSERVATORY
Communicated
July
26,
1944
During
an
investigation
of
colors,
magnitudes,
and
spectral
types
in
the
Hercules-Vulpecula
region,
it
was
noted
that
a
star
at
the
approximate
position
19hl0'6,
+210
37'
(1855),
X
=
230,
X
=
+30
had
a
very
large
color index.
A
preliminary
examination
of blue and
red
plates
indicated
that
the
blue-red
color
index
was
between 6.5
and
7.0
magnitudes.
The
blue-red
and
blue-yellow (international)
color indices
of this star
were
determined
from
polar
comparison
plates,
the
blue
magnitude
from
Cramer
Hi-Speed
plates,
the
red
magnitude
from
Eastman
'103a-E
plates
with
a
cine-red
filter
(effective
wave-length
near
6300
A),
the
yellow
mag-
nitude
from
103a-G
plates
with
a
yellow
filter. The
8-inch
Ross-Lundin
(IR)
refractor
was
used
for the
red and
the
yellow,
the
16-inch
Metcalf
(MC)
refractor
for
the blue
magnitudes.
All
plates
were
taken
between
May
26
and
June
5,
1944.
The
results
were
as
follows:
248
ASTRONOMY:
G.
HARO
PROC.- N.
A.
S.
14
m
75
8m 10
Mag,7
Magp,
C.I.
(blue-red)
C.I.
(blue-yellow)
Mag.,
9"75
6
"65
5'
00
0.10
0.10
This
star
has been
observed
before
by Lee
and his
associates;
it is
No.
129
in
the list of
Dearborn
Annals,
Vol. IV,
Part 16, 1940, where
its
spectral
type
is
given
as
N.
The
star
is
not
unlike the very
red
star
discovered
in 1935 by F. K.
Edmondson
and
A. M.
Rogers.I Both
Edmondson's
star, BN
Monocerotis,
and
the
present object
are
variable.2
An
examination
of
plates
in the
Har-
vard
Collection
gives
the following provisional results:
DATE
MAGpg
Aug. 31,
1897
Sept.
11,
1917
July
5,1926
Oct.
28,
1927
Apr.
18, 1928
Oct.
9, 1928
June
3,
1929
July
15,1929
July
18,1930
May
11, 1937
July
13,1937
May
28,1938
May
30,
1938
Aug.
30, 1940
May
26,
1944
May
28,
1944
May
29,
1944
*
13.55
15.
10
13.80
14.30
14.35
14.10
13.70
13.60
14.00
13.90
13.70
13.60
13.60
14.60
14.80
14.85
14.75
The
finding
of
this
very
red
star
led the
author
to
attempt
a
search
for
other
very
red
stars
in
the
same
region
of
the
sky.
The method
employed
in
this
search
resembles
that
used
previously
by
several astronomers, among
others,
G.
A.
Tikhov,3
V. M.
Slipher4
and
G.
Z.
Dimitroff.5
The
instrument
used
in the
survey
was
again
the 8-inch
Ross-Lundin
(IR)
refractor.
The
region
was
photographed
on an
Eastman 103a-E
plate,
exposure
time
five
minutes
at
normal blue focus and without filter.
Since
the
IR
camera
has
a
very steep
focal
curve,
(1/5
inch distance between blue
and red
focus)
and
the 103a-E
plates
are
sensitive
to
the blue
as
well
as
to
the
red
region
of
the spectrum,
the red
stars
appear
as a
black dot
(blue)
surrounded by
a
strong
red
halo,
when focused for the blue. The halo is
almost
totally
absent
for
the
very
blue
stars,
but
quite
conspicuous
for the
normal
late-type
stars.
The
above-mentioned
star
is
so
red that the blue
VOL.
30,
1944
ASTRONOMY:
G. HARO
249
central
dot
is absent
on a
five-minute exposure;
there appears on the
plate
only a halo of
fairly
uniform brightness with
a central
hole.
The
region
was
photographed
a second time with
the
IR camera,
blue
focus,
103a-E
plates,
no
filter,
and with an exposure
time of thirty
min-
utes.
This
plate revealed the
presence of
three additional
very red stars,
marked
by
a
red
halo
without
the central blue image. The
approximate
positions,
magnitudes
and
color
indices of these stars are:
STAR
2
STAR
3
STAR
4
R.A.
19k
9.2
(1855)
19k
8m
+180
20'
180
+30.5
19i
9m
+170 10'
170
+30
Dec.
X
+240
58'
260
+50
X6
Mag,,
Magp.
Mag,g
C.I.
(blue-red)
CI
(blue-yellow)
16m40
9.90
11.50
15m
60
10.45
5.15
15770
10.35
6.50
0
o"'10
4.90
,
0.10
0'
10
5.35
o"i10
The
spectral
type of
the
second star was
determined
from two plates
taken
by
Miss
Florence
Anderson
with the
12-inch
Metcalf (MA) refractor,
exposure
time
two
hours.
The
spectrum is faint, and resembles
that
of an
N
star.
Following
the search
of
the first field,
discovery plates
were made
for
two
additional
centers,
one
eight
degrees
north,
the other
eight degrees south
of
the first
center,
with
thirty
minutes'
exposure
time.
An
examination
of
these
two
plates
reveals
the
presence
of four
additional
conspicuously
red
stars,
with
a
red
halo,
but
no central
blue
image.
It seems
likely that
the
blue-red
color
index
of
each
of these stars
is well
in excess
of
four
magni-
tudes. The
approximate
1855
positions
from BD-charts
are:
STAR
5
6
7
8
R.A. (1855)
18
587:'3
19
11
19
10
19 16.3
Dsc.
(1855)
+13°
30'
+
8
35
+27 36
+31
2
X
13.5
9
28
31
X
+2°5
-1.5
+6.5
+7
The total
area
covered by
the
present survey
is
approximately
250
square
degrees;
it
is
complete to
the
eleventh
photo-red
magnitude.
The
survey
yields
eight
stars
with
color
indices
(blue-red)
of
more
than
four
magni-
tudes.
It
should
be
noted that
all
stars
are
within
eight
degrees
of
the
galactic
circle.
A
-study
of color
indices
of
stars of known
spectral
type
shows the
average
absorption
for the
region
to
be of the
order
of
one
mag-
nitude
per
kiloparsec.
None
of
the
stars
is found
in
a
region
of
heavy
ob-
scuration
included
in
the
survey.
250
I
BOTANY:
BURKHOLDER,
ETAL.
PROC.
N.
A.
S.
Pub.
A.S.P.,
47,
191
(1935).
2
Ap.
Jour., 100,
1
(1944).
8
A.N.,
218,
145
(1922)
and
Poulkovo
Publ.,
Ser. 2, 50
(1937).
4Pub.
A.A.S.,
7,
15
(1931).
6
The
Telescope,
6, 62
(1939).
ANTIBIOTIC
A
CTI
VITY
OF
LICHENS*
BY PAUL R.
BURKHOLDER,
ALEXANDER W.
EVANS,
ILDA
MCVEIGH
AND
HELEN
K.
THORNTON
OSBORN
BOTANICAL LABORATORY,
YALE
UNIVERSITY
Communicated
July 20,
1944
The
production
by
an
organism
of
organic
substances
inimical
to the
life
processes
of
other
organisms
and
inhibiting
their growth
is
known
as
antibiosis. The phenomenon
of
antibiosis
has
attracted
wide-spread
attention
in
recent
years
chiefly
because
of
the
remarkable
chemothera-
peutic
effects
of
penicillin,
a
product
of the
mold
Penicillium.
The ana-
bolic
products
of
many
kinds
of
bacteria,'
molds,2
and
algae,3 and
sub-
stances
elaborated
by
certain
species
of
flowering
plants4
can
be
readily
demonstrated
to
have
antibiotic
properties
when
small
amounts of
the
active
materials
are
tested
on
microorganisms
with
suitable
assay
pro-
cedures.
In
view
of the
reported
antibacterial
activity
of
the
green
alga
Chlorekla
and the
many
antagonistic
substances
now
known
to
be
produced
by numerous
kinds
of
fungi,
the
lichens
seemed
to
offer
favorable
material
for
antibiotic
investigations, inasmuch
as
the bodies
of
these plants
are
comprised
of
mixtures of
algae
and
fungi.
Accordingly
we
have
tested
a
considerable
number
of
lichens for
antagonistic
action
against
some
com-
mon
species
of
bacteria,
and
offer herewith
a
preliminary
report concern-
ing
some
of
our
observations.
Methods.-The
lichens
were
brought
in fresh condition
to
the
labora-
tory,
placed
in
shallow pans, and
moistened
with
water
for the
purpose
of
allowing them
to
become
physiologically
more
active. After
a
few
hours
of
exposure
to
sunlight,
samples
of
the
moist lichens
were
separated
from
the substrata with
a razor
blade
and
forceps.
Extracts
were
made
by
grinding,
with
a
glass
mortar
and
pestle,
100
mg.
of lichen in 1 ml. of
phos-
phate
buffer
solution
adjusted
to
pH
7.4.
The
final
aqueous
extract
was
approximately
pH
7.0.
Extractions
were
carried
out
at
room
temperature
and the
samples
were
stored
at
1°C.
for
a
short time until the
materials
could
be
assayed.
No
attempt
was
made
to
clarify
the extracts in these
preliminary
tests.
The
aqueous
suspensions
were
assayed
against
Staphy-
lococcus
aureus,
Escherichia
co/i,
Bacillus
subtilis
or
other bacteria
by
means

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