Evening star., 1898-12-31

| edged prince of the consultations, con-
| tanning two stars of the first magnitude,
| hangs in mid-heaVen in the southeast.
! Below Orion flashes with its blue-white
! light the Dog Star, Sirius. nine times as
| brilliant as an average star Of the first
| magnitude, the principal star in the CAMS
| Major. At the left of Sirius, ut about the
! same height, little south of east, is Pro-
| cyon, in the CAMS Minor.
| Above Orion and nearly overhead. as we
| face the south is Taurus the celestial bull
/ his face marked by the N-shaped cluster of
| the Hyades, and the star Aldeharan, the
| Bulls Eye" and in his shoulder the
| sparkling Pleiades. Turning to the east,
| We shall find CaDeIld, the She Goat, ia the
| constellation of Aurga, one Of the bright
est three stars in the northern hemisphere,
well UP toward the zenith Midway be
| tween this star and the horizon are the
Twins (Gemin), Castor and PoliuN, the one
! 4 bright secOnd-magnitude star, the other
usually accounted of the first magnitude.
The Lion Q4eo) is just rising, the Sickle,
which forms his head and shoulders ana
which contains in its handle the bright star
| Regulus, being fairly above the horizon.
| little north of east. The brilliant ruddy
| star now to be seen midway between
Reguius and the Twins is an interloper in
| this part of the heaVenS-the planet Mars,
| fully bright Sirius, though not yet
| shining with its greatest brilliancy for this
year.
The PIanfsphere.
| The position of these and other notable
objects which are now above the horizon
at pm. shown on the "pianisphere"
| given herewith. This chart represents one
entire half of the heavens-the half which
| is now visible at the hour named-its cen
| ter being the zenith, or the point exactly
| overhead circumference hpTiZpp
! To compare il with the heavens one should
| hold it-or imagine it to be held-nearly
| overhead, il such way that the marginal
/ letter which indicates the point in the hOri-
| zon which he faces is lowermost. AS the
| chart lies before now it shows in their
! proper positions the stars in the southern
quadrant of the heavens. If We wish to
| find those in the northern quadrant we
| must turn the chart around, bringing the
letter n. lowermost. We may then see the
Great DipDer standing on its handle be-
tween north and northeast; Cassiopeia
| high in the northwest, while directly be
| fore us. somewhat less than half way from
the horizon to the zenith, stands Polaris,
the Pole Star.
The Pole Star.
The Pole Star. or the North Star as it is
| more often called. may be found easily by
| means of the pointers III the Great Dip
per-the two stars in the bowl which lie
opposite the handle and which are now the
uppermost two. 1t is nearly in line with
these stars. at a distance from the nearer
about equal to the length of the Dipper
| The Pole Star can also be Identified from
its position at the end of the handle of the
Little Dipper-the end OF the tail of the
Little Bear-which is now directly beneath
ii. 1t is well 10 remember. too that this
important star stands midway between
Cassiopeia and the handle of the Great
Dipper. 1t is of the second magnitude, and
is the brightest star in this neighbornood.
Tl1a 1orIyS FL Int net
exactly, the north pole of the heavens. The
true pole is distant from the star and
a quarter degrees, on a line drawn from the
star to Alioth. the innermost of the three
stars which form the handle of the Dipper.
The Pole Star. therefore, is not stationary
in the heavens, as is commonly thought,
but like the rest of the circum-pollr stars,
1t appears TO circle round the true pole, in
an orbit, which, We're it visible, would form
a circle about five times as large, in diam
eter, as the full moon.
Mira, the Wonderful.
This interesting star is now in an excel
lent position for observing, though it has
already passed its maximum for this year
and is rapidly waning.
Mira is the longest known and the most
| remarkable of what are called ''long-period
variables.'' 1t changes in brightness Pc
riodically and with tolerable regularity from
star of less than the ninth magnitude to
a star of the fourth. third. or, occasion
ally, of the second magnitude, going
through its changes in an average period
or 33l days, or eleven months. Since an
average star of any given magnitude is
two and half times bright as star
Of the magnitude next lower, it can easily
be figured out that when Mira is of the
second magnitude it is 625 times as bright
as when it is of the ninth. The cause of
this extraordinary variation in brightness
is among the still unsolvsd problems Of
astronomy. The spectroscope shows that
the stars increase of splendor is due to an
outbreak of .ncandescent gases, Of which
hydrogen and helium appear to be the
most abundant. Sir Norman Lockyer says
that this and similar variables are not
true stars; that is, massive suns, but are
simply condensiug swarms of meteorites.
His theory is that In the case of these
variable stars there are two -swarms of
meteoritcs, one circling round the other in
very elliptical orbit. and that the heh-