Evening star. [volume] (Washington, D.C.) 1854-1972, 1896-05-02

but more particularly because the failure
of DR.. Elkin to discover any ''parallax" in
this star, or in plain English his failure to
obtain any trustworthy indca ton of its
istance compels us to regard it as a sun
of gigantic dimensions, even when compar-
ed with our own enormous Iumnary A
little figuring will make this clear Ac-
cording TO the photometric measurements
of Seidel Arcturus has about one-fifth of
tha brilliancy of Sirius. Now, it has been
estimated that Sirius shines with an in
trinsic light equal 10 that of seventy suns
placed side by side. Hence the combined
light of fifteen suns placed at it's distance
would form star of the brilliancy of Arc
turus.
At double that distance 1t would require
tour times as many suns to form a star
which would appear to equally bright;
at three times that distance the number of
suns must be nine times as large, to keep
up the stars brlliancy, and so on, the num-
Der continually increasing with the square
of the distance. The distance of Sirius is
row pat at about Zen light years" that
is to say, it takes the light of this star ten
years to flash across the interval of space
between it and US. The least distance
which it has been thought could be assign
ed to Arcturus upon the basis of DR.
Elkin's observations, is sixty-seven light
years with a probability that it IS much
greater than this.
Let US be moderate and assume that Arc
turuS is, in round numbers seven times as
far away Sirius. The square of seven is
iorty-nine, and this number multiplied by
fifteen gives 49, the number of suns
which would be required at the distance of
Arcturus to make a star equal to it in
splendor. These would be equivalent to one
sun having a diameter tWenty-seVen times
as great as that of ours. Bear in mind that
ms is a moderate estimate of the size of
the brilliant Bear Warden" with a high
degree of probability that it should be
greatly increased. Our sun at the distance
of Arcturus would be far. below the limits
of the naked eye vision $
The Planets.
Mercury Is now an evening star and may
be seen low in the west a half hour or so
after sunset. Look for it little north of
exact west. 1t will reach its greatest east
ern elongation the 10th of the month,
after which Gate it will rapidly draw in to-
ward the sun. though it will still remain
visible for another week
There is popular notion that Mercury
is very difficult object to see This is an
error. probably due to the fact that much
of our popular astronomy has been derived
from English sources. 1T is true that in
the high latitude of England, owing to the
great inclination of the ecliptic with re-
srect to the horizon. this planet can be
seen well only al certain seasons of the
year, when the conditions are the most
favorable; but in the mean latitude of the
United States Mercury can be seen by one
who knows when and where to look for it
whenever it is near its greatest elongation,
or angular distance from the sun, either
east or west. The average time of it's visi-
bility for is about two weeks On the
present occasion it will be visible, weather
permitting, during nearly the whole month
and no one who is interested in the celestial
goinSs-on should miss this opportunity of
getting good sight of this shy planet
Mercury shines with silvery white light
and at its brightest Is about equal to a star
of the first ma gnitude
Venus continues to be a morning star
rising about ali hour before the SUM- but
she now shines with her least splendor and
her present season, as Lucifer the Morn
ing Star, Is practically closed
Mars also is a morning star rising be-
tween and 3 am. He has just reached
the western border of the constellation
f'lsces, and will soon pass the vernal equi-
htx and enter the northern hemisphere
He therefore now rises almost exactly in
the east.
Jupiter is still a brilliant evening star
and Is well above the horizon at 9 pm in
the position shown on the planisphere.
Note his situation with respect to the
iwins, to Procyon and Regulus The planet
Is SO brilliant that no one can mistake it
for an ordinary star.
The positions of both Saturn and Uranus,
toth evening stars have already been
pointed out and are also marked on the
planisphere. Both planets are now retro
grading or moving toward the west. Nep-
tune. in Taurus, now sets just before 8
o'clock.
The zodiacal Signs now above the hori-
zon at pm, named in order from west to
esst, are Gemni "a part only, Cancer, Leo,
virgo, Libra, Scorpio and part of Sagitta-
rus. ihey are marked on the planisphere
with their respective hieroglyphs.
Inc position of the moon at 0 pm for
every day on which she is above the hori-
zon at that hour is also shown on the plan
lsphere The moon will be new this month
on the 18th at TAG pm, and full on the
18TH at 800 pm, Washington mean time
she Will be in ''perisee"-nearest to the
earth-on the Path, two days before the