Evening star. [volume] (Washington, D.C.) 1854-1972, 1898-04-02

81 PM
the feet bears the Arabic name Alchiba
which means tent" and was doubtless
applied originally to the whole constella-
ton, which certainly resembles tent
quite as closely as it does bird.
Few Star Distances.
One of the most impressive of astro-
nomical discoveries is that of the enormous
remoteness Of the stars. We will look from
this point of view at few of the stars
which may be seen tonight.
Formerly it was supposed, in the absence
of evidence to the contrary, that the
brightest stars were the nearest to us.
This would be the case, of course, were
the stars all of about the same size and
of the same intrinsic splendcr. Blu. recent
investiga tons have shown that such Is
very far from being the case. One of the
nearest of the stars, 81 Cygni, is of only
the fifth magnitude, while Sirius, at
distance of between eight and nine Tight
years." according to the determinations of
Drs. Gill and Elkin, though the brightest
of the stars, stands third in the order of
distance. Still, it may reasonably be as
stunned that on an average the brighter
stars are the nearer. and that en- the whole
star distances increase as star magnitudes
diminish. A knowledge of the distance of
the stars of the first magnitude should
therefore, give us a fairly correct idea of
travel In journeying outward to the region
of the telescope stars.
Some ten years ago DR.. Elkn made
series of observations, with the heliometer
of the Yale College Observatory, for the
purpose Of determining the distances of the
ten first magnitude stars Of the northern
hemisphere, while DR.. Gill, at the Cape of
Coco Hope. undertook like study of those
OF the southern hemisphere. The conclu-
sion reached by DR.. Elkin was that the
average distance of these stars is not less
than thirty-six and half light years."
That is to say. light, which flashes
second, reaching US from the, sun in eight
and quarter minutes, requires more than
third of a century to come 10 us from a
point In space at the average distance of
the ten first magnitude stars of the north
ern hemisphere. The sun removed to that
distance would dwindle te a star Of the
seventh magnitude, and would be lost to
the naked eye. -,
Measured by Years.
The nearest of these stars, according to
DR.. Elkin. is Procyon, of which the dis
lance is given as 12.4 light years. Affair,
one of the ten not visible tonight, comes
next at a distance of 1853 light years. Next
comes Aldebaran, at 2S light years. Capel-
la and Regulus are at about the mean dis
lance OF SO light years. In the cases of
the remaining five stars the quantity to be
me assured proved to be so minute that little
confidence could be placed in the results
obtained, farther than to regard them
liking minimum for the distances of these
stars. Thus, sixty-seven years was con-
sidered to be the least distance which could
be assigned to Arcturus. with the proba-
bility that actually it's distance is much
greater than this. Astronomers speak Of
this star, indeed, as not improbabiy two
hundred light years distant from us, and
Miss Agnes Clerke, in her System Of the
Stars, regards 1t as perhaps the most
m
DR.. Gill has come to a conclusion respect
ing the distance Of Rigel which, if accept
ed, compels US to conceive Of this star as
dwarfing even Arcturus. DIR. Gill thinks
that the distance Of Rigel is more than
twenty million times that Of the SUN, dis
lance which would give 1t q Eight journey
of $40 years, or more than thirty times that
of Sirius. In order to shine for US as bril-
liantly as it does at that unthinkable dis
lance 1t must emit light equal in amount
upon moderate estimate, to that Of 1900
suns. There Is something so astounding in
this conclusion that one Is strongly in
clined to suspect that some essential mat
ter has been overlooked by DR.. Gill, which,
If considered, would have lessened his con-
fdence In his result. Indeed, the present
method of determining star distances is adj
mitted by all astronomers to have an ele-
ment of weakness which cannot easily be
eradicated, and to be, for that reason, not
as reliable as could be wished. If the star
comparison stars" used in the observa-
tions, happen to be at about the same dis
tance from us-and there is no way Of tell
ing offhand whether this is the case or not
then the method employed breaks down,
and the result obtained is misleading.
There is really a good deal of guesswork,
as well as very difficult observation, in
volved In the determination of the distance
Of star. Still. as to the main truth that
even the nearest Of the stars are enormous
ly remote-so remote that we must con-
ceive of them as suns comparable with our
own sun in size, and in many cases vastly
larger than 1t. there. Is no room for doubt.
The Planets.
Mercury will be an evening star through
out the month, and should be visible dur
ing the ensuing two weeks or longer. 1t
will be at its greatest elongation east from
the sun-10 degrees 81 minutes the 10th.
Look for .t half hour or less after sunset
q little north of west.
Venus also is an evening star and Is now
far enough east Of the spp ote be visible.
It will be situated tonight about four de-
grees below Mercury. or, Il
Mars is a morning star. in Aauarius. ris-
ing little south OF east at about am.
Jupiter is now splendid ornament Of the
evening sky, about four degrees west OF
Gamma Virgins. It was In opposition to
the sun on the 18th Of last month. and it
Is therefore now at its least distance from
us for this year and shiheS with its great
est brilliancy. Its retrograde, or westward
due to the fact that we are
now passing 1t in the grspd Face around
the sun. can readily be observed by noting
its change Of position from night to night
with reference to the neig6boriAg stars.
Saturn and Uranus are evening stars In
the Scorpion. and rise at about II pm At
about the same hour Neptupe. in Taurus.
sets.
The rcte Of the growthrof human hair
varies. In some cases Il has been known
to exceed two inches per month. The