Evening star. [volume] (Washington, D.C.) 1854-1972, 1901-10-05
THE OCTOBER SKY
Milky Way Arches Now From
Northeast to Southwest.
CONSULTATIONS EASY TO LOCATE
Discovery of the First Spectre
scopic Binary Star
THE ORIONIDS METEORS
Written for The Evening Star.

| Written for The Evening Star
| Five stars of the first magnitude are
now above the horizon at pm They are
Fomalhaut, low in the south; Vega and AL
| tair, in midheavens in the west, the for
mer on our right. the latter on our left. as
we face in that direction; Capella. in the
| northeast, at about the same altitude as
Fomalhaut Aldebaran, barely above the
horizon little north of east
| Consultations.
The Milky Way now passes at the hour
| named very nearly overhead, arching the
| heavens in a direction from northeast to
southwest In it or along it are the con-
| stellations Sagittarius, partly below the
horizon in the southwest, Ophiuchus, the
Eagle, the Dolphin. the Swan, Cepheus,
| CaSsiopeia PerseuS and Auriga.
| Auriga. the Wagner, can be located by
| means of the brilliant star Capella, the
| She-goat, which stands in his left shoulder,
| his right being marked by the star Beta.
| of the second magnitude. Cassiopeia, the
| Lady-in-her-chair, is easily Identified from
the W-shaped figure formed by its five
| brighter stars. Midway between Capella
| and the lowest Of the bright stars in CASH
| opeia, at the right of a straight line drawn
| from one to the other of these two stars,
| stands Alpha Persei, a star of the second
| magnitude, in the breast of Perseus. This
| constellation, lying in the Milky Way. is
| rich in stars, containing, according to Bur-
| rift, sixty-seven that are visible to the
naked eye. An elongated group Of dozen
1 or more forms the body: the right hand is
raised aloft. the constellation is depict
| ed upon charts, and brandishes sword,
| while the left holds by its snaky locks the
| frightful Medusa head, in the forehead of
| which stands the famous variable star Be
| ia, better known by its Arabic name, AL
gol, the Demon.
At the right Of Perseus the observers
| right and in midheavens in the east re-
clines Andromeda. Still farther to the east
| and at q greater. altitude Is Pegasus. A
| large dipper-shaped group Of seven stars
| Of the second magnitude forms the basis of
| these three consultations and renders their
| location easy. The great square of Pega-
sus forms the bowl Of this dipper; Alpha
| Persei forms the end Of the handle. while
| Of the four. which form the square belong
| to Andromeda.
| Midway between Andromeda and the
| eastern horizon is a conspicuous pair of
stars, one Of the second and one of the
| third magnitude, which mark the head of
| Aries. the Ram. Below and at the left of
| Aries stands the well-known cluster Of the
| Pleiades, in the shoulder OF Taurus, the
| Bull, whose head. marked by the star AL
| debaran and the cluster of the Hyades, has
but just now appeared above the horizon.
| Below and at the right of the head of
! Aries. forming with 1t and the Pleiades a
| large equilateral triangle, is Menkar a star
| of the second magnitude. in the head of
| Cerus. Deneb Kaitos, also a star of the
| second magnitude, in the tail of this mon
| ster, stands in the southeast at about
| three-fifths Of the distance from Menkar
| to Fomalhaut. Cetus Is one of the largest
| Of the consultations, but the region ii COW
| ers is generally poor in stars. The constel-
| lation is interesting chiefly for its remarka-
| BILE variable star Omicron. better known as
| Mira, the Wonderful. The range of the va
Inability of this star. the period of which
| Is about eleven months, is from the ninth
| to the third and occasionally to the sec
ond magnitude. The last maximum of Mi
| "a, when it was Of about the third magni-
| tude occurred near the close of last June
| The star Is not now visible to the naked
4 eye.
Interesting Stars.
Among the stars that may be seen this
! evening are several which have been
brought into prominence through investi-
| cation with the spectroscope. One of the
| easiest to locate Of these very interesting
| stars is Mizar CZeta Ursae Majoris), the
| middle star in the handle Of the Great
Dipper. With even small telescope Mar
can be seen to be double star, and very
pretty object 1t Is for such an instrument
| 1t is said, indeed, to be the first discovered
of the double stars, Of which several thou
sand are now catalogued and probably be-
| cause of the ease with which it can be
identified 1t has been the first double star
seen by many an amateur telescopist as it
was the first ever seen by the present
writer.
| Some twelve years ago Prof E. c. Pick
ering director of the Harvard College OBJ
4 servatory, announced that from an exam
| nation of q series Of photographs of the
spectrum of Mizar 1t had been discovered
| that there was a periodical doubling of
\ the dark lines of this spectrum, whsnca he
| concluded that there were really two spec-
| ira in the case one superposed upon the
other. or, In other words, that there we're
| two stars here, although the pair which
| they formed was SO close as to be unre-
l-solvable with the largest telescope. The
| doubling Of the lines, due to a slight rcla-
| tive shifting Of the spectra, could be ac-
counted for easily on a well-establisllei
| spectroscopic principle by the supposition
that the two stars were revolving about
each other in a plane set nearly edgewise
| to us. The doubling occurred at intervals
of ffty-two days. and since the explana-
| ton required that It should occur twice in
| each revolution this gave the star a period
| Of lO4 days.
Thus was made the first discovery OF a
''spectroscopic binary star" The list Of
| such stars-that is to say, Of stars which
| though they appear single even when ex-
amined through the largest telescope are
| found by means Of the spectroscope to con-
other. like the two balls of dumb-bell
1 tossed into the airs already quite a long
one. The first four or five OF these stars
were discovered at the Harvard College OBJ
Aurigae. The most OF the recent discoy-
cries OF this kind have been made at the
Lick observatory.
To return to Mizar, DIR. II. G. voxeL d.
rector Of the Potsdam observatory, has re-
ported recently that from a series OF photo
with the new refractor OF that observatory
he has found the period of this binary star
to be 20.6 days instead Of l04 days, as has