Evening star. [volume] (Washington, D.C.) 1854-1972, 1895-01-26


estimated comes out, in round numbers,
$50 light years''-twenty- times that Of
Sirius, which, as we have just seen, is
100000 times that of the sun. The cluster
| is roughly globular, with an apparent
| diameter about three times that Of the
| moon. Its distance being known, its act
ual diameter be calculated. 1t is such
| that light requires seven years to speed
across the cluster from side to side. Were
| its central star In the place of the sun the
outermost stars of the globular portion of
| the cluster would be found nearly at the
distance Of Alpha Centauri, the suns near
est stellar neghbor, while its outlying
streamers would extend far beyond. The
sun at the distance Of the Pleiades would
dwindle to star of the tenth magnitude.
1t would require a telescope of some size
to disco!er it. Alcyone surpasses it in
splendor If these figures are correct, 1000
| times. IN view Of lurinary such as this,
even Sirius can no longer be called n
giant SUM-
Among the attractions for this month
| may be reckoned a probable maximum"
of the variable star Mira Ceti. The pc
culiarity of this star, to which it owes its
name the wonderful" Is this: Ordinarily
at its minimum of brilliancy, of between
the ninth and tenth magnitudes. After re-
naming thus for some weeks 1t begins to
brighten, and after while it becomes Wis
ible TO the naked eye. It continues to
brighten for some six weeks longer, when
it attains it's maximum of brilliancy. which
may be anywhere between the fourth and
second magntudeS, for the star is some
what capricious in this respect Then 1t
begins to wane, and at the end of about
three months it is again lost to the naked
eye.
Mira runs the cycle of its changes in an
average period of eleven months. from
which it may deviate to the extent of
thirty days. Its last maximum. when 1t at
tanned very nearly to the second magni-
tude. was in March last. Another return
to brilliancy is, therefore, due this month.
At the time of writing January 12) 1t has
not become visible to the naked eye. but it
can be seen with opera glass.
The star should be looked for early in the
evening. At $50 pm. on the LIST Of Febru-
airy it is exactly south. 1t can be found
thus: The star Menkar in the head of
Cetus, a star of the second magnitude
forms, with the Pleiades and the pair of
stars in the Rams Head, an equllaterai
triangle. A straight line run from Aide
baran through Menkar and continued about
one-half far beyond will end very near
Mira. There is no star near 1T of above the
sixth magnitude.
Diagram of Zodiac.
The die gram showing the positions OF
the sun and the planets is set for pm.
on the 1st of the month. it's upper half rep
resenting the half Of the zodiac which Is
then above the horizon.
Five Of the planets - Mercury, Venus,
Mars, Neptune and Jupiter-are now east
ward from the sun, the last three being
above the horizon at the hour named.
Uranus and Saturn are westward from the
sun-so far west that both will rise before
midnight. All of the planets are now ''even-
ing stars
At the close Of the month the sun will
have advanced one Sign to the eastward
(taking with it Mercury and Venus), and
the horizon will then be as indicated by the
dotted line, the three planets still being
above it, but lower in the west.
The arrows attached to Mercury and
amount of their movement with relation
to the sun during the month. Mercury will
advance from the sun until the 9th, when
it will attain it's greatest elongation east.
For few days about this time it should
be visible after sunset, low in the south
west. 1t will then draw in toward the sun
and will be in conjunction with the sun
Gnferor) on the 18th.
Venus is drawing away from the sun and
should become visible by the end of the
month.