Evening star., 1901-06-29
THE SKIES IN JULY
Many Facts of Interest to Amateur
Astronomers.
TO LOCATE STARS And PLANETS
Direction in Which the Sun Moves
Through the Heavens.
CONSULTATIONS IN VIEW
Written for The Evening Star.

OLA STATS VI the magnitude VIII De
above the horizon at Q o'clock this evening.
Named in the order of their brlliancy they
are Arcturus, at one-third Of the distance
from the zenith to the southwestern hori-
zon; Vega or Alpha Lyrae, at the same al
titude, a trifle north Of east: Affair, in
the Eagle. at one-third Of the distance
from horizon to zenith, between east and
southeast; Spica, the principal star in
Virgo. midway between Arcturus and the
southwestern horizon; Antares, the Scor-
pion's Heart. at about the same altitude
directly south; Regulus, in Leo. just set
ting, little north Of west.
The bright red star midway between
Regulus and Spica is the planet Mars
The very brilliant white star seen low In
the southeast is Jupiter. About five de-
grees farther east is Saturn.
By the close of the month all Of these
objects will be thirty degrees farther west
at pm. Regulus will no longer be above
the horizon Mars will be too low to be
seen well. while Jupiter and Saturn will be
nearly south.
Consultations.
Very nearly overhead at the hour named
may be seen the Northern Crown No one
can fail to recognize this beautiful aster-
ism. nearly complete oval formed by six
or eight stars, Of which the brightest, Al
phacca, the Pearl of the Crown" is of
the second magnitude. At the right Of
the Crown. as We face the south. stands
Bootes, the Herdsman, a constellation by
no means easy to make out and interest
ing mainly for its brilliant Arcturus Gin
the left knee). Arcturus. Alphacca and
Gamma Boots, a third-magnitude star in
the Herdsman's left shoulder, form an
equal-sided triangle, which is one of the
landmarks Of this region Of the heavens.
At the center OF this triangle stands the
star Epsilon Bootis, of the third magni-
tude, star which, had We a good four
inch telescope, We might find to be dou-
BILE star, having close beside 1t a small COM
panton Of an olive green color. The star
is here mentioned because Of its reputa-
tion among telescope-using star gazers as
one Of the prettiest Of the colored doubles
Arcturus is for several reasons an espe-
cially interesting star. 1t Is, to begin
with, one of the celestial objects mention
authorized version of the Scriptures,
though scholars are now inclined to think
that the Great Dipper Is there referred to
rather than single star. 1t will be no.
ticed that it's color is a deep orange. The
analysis of it's light with the spectroscope
has shown that it is a body nearly identi-
cal, both in composition and in physical
condition, with the sun, its spectrum being.
according to Sir Norman Lockyer. essen
TALLY the same as the solar spec
trum so far as its feebler light permits
comparison to be made. Arcturus is un-
doubtedly, however a very much larger
body than the sun, although as yet all at
tempts to obtain trustworthy data for de-
termining its distance, and thus a means
Of estimating its size, have been unsuc-
cesSful- DR.. Ekin has reached the con-
clusion, as one result Of an Intellectual at
tempt to measure it's "parallax," that the
minimum distance which can be assigned
to this star is 81 light years" The sun
removed to that distance would become
for us a star Of the sixth magnitude.
Hercules, the KneeIer.
With the aid Of the sketch given on our
chart this constellation should easily be
located Observe that the head. which is
marked by the star Alpha Herculis. va
riable ranging from the third to the fourth
magnitude, is toward the south, and Is near
that of Ophiuchus-five degrees west Of It,
The body Of Hercules, or rather the lower
portion Of his body, Is formed by q ira
pezium Of four third magnitude stars, a
quite noticeable figure. midway between the
Crown and the Lyre. The left arm mark
ed by line of five or six fifth magni-
tude stars, Is stretched out toward the
Lyre. Hercules is in a kneeling posture
each knee and each foot being marked by
a star OF the fourth magnitude. The figure
sketched here can easily be made out, and
there can hardly be much doubt that this
Is the figure seen by the ancient constella-
tion makers. The old Greek name Of the
COuSteudlIol, tAo ny WHICH II Is re-
ferred to by Aratus. was Engonasin. "On
knees" or, as the name Is commonly rem
dered, The Kneeler. This constellation is
interesting as containing the point-marked
on our chart with a cross and the letter Fl
which Sir William Herschel fixed upon as
that toward which the sun, with his family
Of planets. Is travelling through space
Other astronomers have located this point
the "apex Of the suns way" as 1t Is
called-somewhere hereabouts, though no
two have fixed upon precisely the same
point. The latest and most exhaustive dis
cussion Of all the data available for decid-
ing this question. by Prof. Newcomb has
located the "apex" about four degrees
south OF the star Vega in the const citation
Lyra- The rate Of the suns movement in
this direction has been calculated to be
about $50 900 miles year.
A Complicated Problem.
How, it may be asked, is it possible to
tell in what direction the sun is moving
through space, or whether, indeed, 1t is
moving at all? Difficult Of solution as the
problem is actually, the principal involved
is one Of the most simple and familiar.
When we move in any direction all sur
rounding objects appear to move in the
contrary direction; they seem to move from
the point toward which We are going and
toward the point directly behind us. Were
the sun the only moving star in the uni
verse-were all the other stars fixed, like
the trees in a forest. and were our convey
ance- alone in motion-there would be little
difficulty in determining the direction in
which we were going. We should need
merely to observe attentively the apparent