THE STARS OF AUTUMN.
IN the "Fifth Evening" of that delightful, old, out-of-date book of
Fontenelle's, on the "Plurality of Worlds," the Astronomer and the
Marchioness, who have been making a wonderful pilgrimage through the
heavens during their evening strolls in the park, come at last to the
starry systems beyond the "solar vortex," and the Marchioness
experiences a lively impatience to know what the fixed stars will turn
out to be, for the Astronomer has sharpened her appetite for marvels.
"Tell me," says she, eagerly, "are they, too, inhabited like the
planets, or are they not peopled? In short, what can we make of them?"
The Astronomer answers his charming questioner, as we should do to-day,
that the fixed stars are so many suns. And he adds to this information a
great deal of entertaining talk about the planets that may be supposed
to circle around these distant suns, interspersing his conversation with
explanations of "vortexes," and many quaint conceits, in which he is
helped out by the ready wit of the Marchioness.
Finally, the impressionable mind of the lady is overwhelmed by the
grandeur of the scenes that the Astronomer opens to her view, her head
swims, infinity oppresses her, and she cries for mercy.
"You show me," she exclaims, "a perspective so interminably long that
the eye can not see the end of it. I see plainly the inhabitants of the
earth; then you cause me to perceive those of the moon and of the other
planets belonging to our vortex (system), quite clearly, yet not so
distinctly as those of the earth. After them come the inhabitants of
planets in the other vortexes. I confess, they seem to me hidden deep in
the background, and, however hard I try, I can barely glimpse them at
all. In truth, are they not almost annihilated by the very expression
which you are obliged to use in speaking of them? You have to call them
inhabitants of one of the planets contained in one out of the infinity
of vortexes. Surely we ourselves, to whom the same expression applies,
are almost lost among so many millions of worlds. For my part, the earth
begins to appear so frightfully little to me that henceforth I shall
hardly consider any object worthy of eager pursuit. Assuredly, people
who seek so earnestly their own aggrandizement, who lay schemes upon
schemes, and give themselves so much trouble, know nothing of the
vortexes! I am sure my increase of knowledge will redound to the credit
of my idleness, and when people reproach me with indolence I shall
reply: 'Ah! if you but knew the history of the fixed stars!'"
It is certainly true that a contemplation of the unthinkable vastness of
the universe, in the midst of which we dwell upon a speck illuminated by
a spark, is calculated to make all terrestrial affairs appear
contemptibly insignificant. We can not wonder that men for ages regarded
the earth as the center, and the heavens with their lights as tributary
to it, for to have thought otherwise, in those times, would have been to
see things from the point of view of a superior intelligence. It has
taken a vast amount of experience and knowledge to convince men of the
parvitude of themselves and their belongings. So, in all ages they have
applied a terrestrial measure to the universe, and imagined they could
behold human affairs reflected in the heavens and human interests
setting the gods together by the ears.
[Illustration: MAP. 14.]
This is clearly shown in the story of the constellations. The tremendous
truth that on a starry night we look, in every direction, into an almost
endless vista of suns beyond suns and systems upon systems, was too
overwhelming for comprehension by the inventors of the constellations.
So they amused themselves, like imaginative children, as they were, by
tracing the outlines of men and beasts formed by those pretty lights,
the stars. They turned the starry heavens into a scroll filled with
pictured stories of mythology. Four of the constellations with which we
are going to deal in this chapter are particularly interesting on this
account. They preserve in the stars, more lasting than parchment or
stone, one of the oldest and most pleasing of all the romantic stories
that have amused and inspired the minds of men--the story of Perseus and
Andromeda--a better story than any that modern novelists have invented.
The four constellations to which I refer bear the names of Andromeda,
Perseus, Cassiopeia, and Cepheus, and are sometimes called,
collectively, the Royal Family. In the autumn they occupy a conspicuous
position in the sky, forming a group that remains unrivaled until the
rising of Orion with his imperial _cortege_. The reader will find them
in Map No. 14, occupying the northeastern quarter of the heavens.
This map represents the visible heavens at about midnight on September
1st, ten o'clock P. M. on October 1st, and eight o'clock P. M. on
November 1st. At this time the constellations that were near the
meridian in summer will be found sinking in the west, Hercules being low
in the northwest, with the brilliant Lyra and the head of Draco
suspended above it; Aquila, "the eagle of the winds," soars high in the
southwest; while the Cross of Cygnus is just west of the zenith; and
Sagittarius, with its wealth of star-dust, is disappearing under the
horizon in the southwest.
Far down in the south the observer catches the gleam of a bright lone
star of the first magnitude, though not one of the largest of that
class. It is Fomalhaut, in the mouth of the Southern Fish, Piscis
Australis. A slight reddish tint will be perceived in the light of this
beautiful star, whose brilliance is enhanced by the fact that it shines
without a rival in that region of the sky. Fomalhaut is one of the
important "nautical stars," and its position was long ago carefully
computed for the benefit of mariners. The constellation of Piscis
Australis, which will be found in our second map, does not possess much
to interest us except its splendid leading star. In consulting Map 15,
the observer is supposed to be facing south, or slightly west of south,
and he must remember that the upper part of the map reaches nearly to
the zenith, while at the bottom it extends down to the horizon.
[Illustration: MAP 15.]
To the right, or west, of Fomalhaut, and higher up, is the constellation
of Capricornus, very interesting on many accounts, though by no means a
striking constellation to the unassisted eye. The stars Alpha ([alpha]),
called Giedi, and Beta ([beta]), called Dabih, will be readily
recognized, and a keen eye will perceive that Alpha really consists of
two stars. They are about six minutes of arc apart, and are of the third
and the fourth magnitude respectively. These stars, which to the naked
eye appear almost blended into one, really have no physical connection
with each other, and are slowly drifting apart. The ancient astronomers
make no mention of Giedi being composed of two stars, and the reason is
plain, when it is known that in the time of Hipparchus, as Flammarion
has pointed out, their distance apart was not more than two thirds as
great as it is at present, so that the naked eye could not have detected
the fact that there were two of them; and it was not until the
seventeenth century that they got far enough asunder to begin to be
separated by eyes of unusual power. With an ordinary opera-glass they
are thrown well apart, and present a very pretty sight. Considering the
manner in which these stars are separating, the fact that both of them
have several faint companions, which our powerful telescopes reveal,
becomes all the more interesting. A suggestion of Sir John Herschel,
concerning one of these faint companions, that it shines by reflected
light, adds to the interest, for if the suggestion is well founded the
little star must, of course, be actually a planet, and granting that,
then some of the other faint points of light seen there are probably
planets too. It must be said that the probabilities are against
Herschel's suggestion. The faint stars more likely shine with their own
light. Even so, however, these two systems, which apparently have met
and are passing one another, at a distance small as compared with the
space that separates them from us, possess a peculiar interest, like two
celestial fleets that have spoken one another in the midst of the ocean
of space.
The star Beta, or Dabih, is also a double star. The companion is of a
beautiful blue color, generally described as "sky-blue." It is of the
seventh magnitude, while the larger star is of magnitude three and a
half. The latter is golden-yellow. The blue of the small star can be
seen with either an opera- or a field-glass, but it requires careful
looking and a clear and steady atmosphere. I recollect discovering the
color of this star with a field-glass, and exclaiming to myself, "Why,
the little one is as blue as a bluebell!" before I knew that that was
its hue as seen with a telescope. Trying my opera-glass upon it I found
that the color was even more distinct, although the small star was then
more or less enveloped in the yellow rays of the large one. The distance
between the two stars in Dabih is nearly the same as that between the
components of [epsilon] Lyrae, and the comparative difficulty of
separating them is an instructive example of the effect of a large star
in concealing a small one close beside it. The two stars in [epsilon]
Lyrae are of nearly equal brightness, and are very easily separated and
distinguished, but in [beta] Capricorni, or Dabih, one star is about
twenty times as bright as the other, and consequently the fainter star
is almost concealed in the glare of its more brilliant neighbor.
With the most powerful glass at your disposal, sweep from the star Zeta
([zeta]) eastward a distance somewhat greater than that separating Alpha
and Beta, and you will find a fifth-magnitude star beside a little
nebulous spot. This is the cluster known as 30 M, one of those
sun-swarms that overwhelm the mind of the contemplative observer with
astonishment, and especially remarkable in this case for the apparent
vacancy of the heavens immediately surrounding the cluster, as if all
the stars in that neighborhood had been drawn into the great assemblage,
leaving a void around it. Of course, with the instrument that our
observer is supposed to be using, merely the _existence_ of this solar
throng can be detected; but, if he sees that it is there, he may be led
to provide himself with a telescope capable of revealing its glories.
Admiral Smyth remarks that, "although Capricorn is not a striking
object, it has been the very pet of all constellations with
astrologers," and he quotes from an old almanac of the year 1386, that
"whoso is borne in Capcorn schal be ryche and wel lufyd." The
mythological account of the constellation is that it represents the goat
into which Pan was turned in order to escape from the giant Typhon, who
once on a time scared all the gods out of their wits, and caused them to
change themselves into animals, even Jupiter assuming the form of a ram.
According to some authorities, Piscis Australis represents the fish into
which Venus changed herself on that interesting occasion.
Directly above Piscis Australis, and to the east or left of Capricorn,
the map shows the constellation of Aquarius, or the Water-Bearer. Some
say this commemorates Ganymede, the cup-bearer of the gods. It is
represented in old star-maps by the figure of a young man pouring water
from an urn. The star Alpha ([alpha]) marks his right shoulder, and Beta
([beta]) his left, and Gamma ([gamma]), Zeta ([zeta]), Eta ([eta]), and
Pi ([pi]) indicate his right hand and the urn. From this group a current
of small stars will be recognized, sweeping downward with a curve toward
the east, and ending at Fomalhaut; this represents the water poured from
the urn, which the Southern Fish appears to be drinking. In fact,
according to the pictures in the old maps, the fish succeeds in
swallowing the stream completely, and it vanishes from the sky in the
act of entering his distended mouth! It is worthy of remark that in
Greek, Latin, and Arabic this constellation bears names all of which
signify "a man pouring water." The ancient Egyptians imagined that the
setting of Aquarius caused the rising of the Nile, as he sank his huge
urn in the river to fill it. Alpha Aquarii was called by the Arabs
Sadalmelik, which is interpreted to mean the "king's lucky star," but
whether it proved itself a lucky star in war or in love, and what
particular king enjoyed its benign influence and recorded his gratitude
in its name, we are not informed. Thus, at every step, we find how
shreds of history and bits of superstition are entangled among the
stars. Surely, humanity has been reflected in the heavens as lastingly
as it has impressed itself upon the earth.
Starting from the group of stars just described as forming the
Water-Bearer's urn, follow with a glass the winding stream of small
stars that represent the water. Several very pretty and striking
assemblages of stars will be encountered in its course. The star Tau
([tau]) is double and presents a beautiful contrast of color, one star
being white and the other reddish-orange--two solar systems, it may be,
apparently neighbors as seen from the earth, in one of which daylight is
white and in the other red!
Point a good glass upon the star marked Nu ([nu]), and you will see,
somewhat less than a degree and a half to the west of it, what appears
to be a faint star of between the seventh and eighth magnitudes. You
will have to look sharp to see it. It is with your mind's eye that you
must gaze, in order to perceive the wonder here hidden in the depths of
space. That faint speck is a nebula, unrivaled for interest by many of
the larger and more conspicuous objects of that kind. Lord Rosse's great
telescope has shown that in form it resembles the planet Saturn; in
other words, that it consists apparently of a ball surrounded by a ring.
But the spectroscope proves that it is a gaseous mass, and the
micrometer--supposing its distance to be equal to that of the stars, and
we have no reason to think it less--that it must be large enough to fill
the whole space included within the orbit of Neptune! Here, then, as has
been said, we seem to behold a genesis in the heavens. If Laplace's
nebular hypothesis, or any of the modifications of that hypothesis,
represents the process of formation of a solar system, then we may
fairly conclude that such a process is now actually in operation in this
nebula in Aquarius, where a vast ring of nebulous matter appears to have
separated off from the spherical mass within it. This may not be the
true explanation of what we see there, but, whatever the explanation is,
there can be no question of the high significance of this nebula, whose
shape proclaims unmistakably the operation of great metamorphic forces
there. Of course, with his insignificant optical means, our observer can
see nothing of the strange form of this object, the detection of which
requires the aid of the most powerful telescopes, but it is much to know
where that unfinished creation lies, and to see it, even though
diminished by distance to a mere speck of light.
Turn your glass upon the star shown in the map just above Mu ([mu]) and
Epsilon ([epsilon]). You will find an attractive arrangement of small
stars in its neighborhood. The star marked 104 is double to the naked
eye, and the row of stars below it is well worth looking at. The star
Delta ([delta]) indicates the place where, in 1756, Tobias Mayer
narrowly escaped making a discovery that would have anticipated that
which a quarter of a century later made the name of Sir William Herschel
world-renowned. The planet Uranus passed near Delta in 1756, and Tobias
Mayer saw it, but it moved so slowly that he took it for a fixed star,
never suspecting that his eyes had rested upon a member of the solar
system whose existence was, up to that time, unknown to the inhabitants
of Adam's planet.
Above Aquarius you will find the constellation Pegasus. It is
conspicuously marked by four stars of about the second magnitude, which
shine at the corners of a large square, called the Great Square of
Pegasus. This figure is some fifteen degrees square, and at once
attracts the eye, there being few stars visible within the
quadrilateral, and no large ones in the immediate neighborhood to
distract attention from it. One of the four stars, however, as will be
seen by consulting Map 15, does not belong to Pegasus, but to the
constellation Andromeda. Mythologically, this constellation represents
the celebrated winged horse of antiquity:
"Now heaven his further wandering flight confines,
Where, splendid with his numerous stars, he shines."
The star Alpha ([alpha]) is called Markab; Beta ([beta]) is Scheat, and
Gamma ([gamma]) is Algenib; the fourth star in the square, belonging to
Andromeda, is called Alpheratz. Although Pegasus presents a striking
appearance to the unassisted eye, on account of its great square, it
contains little to attract the observer with an opera-glass. It will
prove interesting, however, to sweep with the glass carefully over the
space within the square, which is comparatively barren to the naked eye,
but in which many small stars will be revealed, of whose existence the
naked-eye observer would be unaware. The star marked Pi ([pi]) is an
interesting double, which can be separated by a good eye without
artificial aid, and which, with an opera-glass, presents a fine
appearance.
And now we come to Map No. 16, representing the constellations Cetus,
Pisces, Aries, and the Triangles. In consulting it the observer is
supposed to face the southeast. Cetus is a very large constellation, and
from the peculiar conformation of its principal stars it can be readily
recognized. The head is to the east, the star Alpha ([alpha]), called
Menkar, being in the nose of this imaginary inhabitant of the
sky-depths. The constellation is supposed to represent the monster that,
according to fable, was sent by Neptune to devour the fair Andromeda,
but whose bloodthirsty design was happily and gallantly frustrated by
Perseus, as we shall learn from starry mythology further on.
Although bearing the name Cetus, the Whale, the pictures of the
constellation in the old maps do not present us with the form of a
whale, but that of a most extraordinary scaly creature with enormous
jaws filled with large teeth, a forked tongue, fore-paws armed with
gigantic claws, and a long, crooked, and dangerous-looking tail. Indeed,
Aratus does not call it a "whale," but a "sea-monster," and Dr. Seiss
would have us believe that it was intended to represent the leviathan,
whose terrible prowess is celebrated in the book of Job.
[Illustration: MAP 16.]
By far the most interesting object in Cetus is the star Mira. This is a
famous variable--a sun that sometimes shines a thousand-fold more
brilliantly than at others! It changes from the second magnitude to the
ninth or tenth, its period from maximum to maximum being about eleven
months. During about five months of that time it is completely invisible
to the naked eye; then it begins to appear again, slowly increasing in
brightness for some three months, until it shines as a star of the
second magnitude, being then as bright as, if not brighter than, the
most brilliant stars in the constellation. It retains this brilliance
for about two weeks, and then begins to fade again, and, within three
months, once more disappears. There are various irregularities in its
changes, which render its exact period somewhat uncertain, and it does
not always attain the same degree of brightness at its maximum. For
instance, in 1779, Mira was almost equal in brilliance to a
first-magnitude star, but frequently at its greatest brightness it is
hardly equal to an ordinary star of the second magnitude. By the aid of
our little map you will readily be able to find it. You will perceive
that it has a slightly reddish tint. Watch it from one of its maxima,
and you will see it gradually fade from sight until, at last, only the
blackness of the empty sky appears where, a few months before, a
conspicuous star was visible. Keep watch of that spot, and in due course
you will perceive Mira shining there again--a mere speck, but slowly
brightening--and in three months more the wonderful star will blaze
again with renewed splendor.
Knowing that our own sun is a variable star--though variable only to a
slight degree, its variability being due to the spots that appear upon
its surface in a period of about eleven years--we possess some light
that may be cast upon the mystery of Mira's variations. It seems not
improbable that, in the case of Mira, the surface of the star at the
maximum of spottedness is covered to an enormously greater extent than
occurs during our own sun-spot maxima, so that the light of the star,
instead of being merely dimmed to an almost imperceptible extent, as
with our sun, is almost blotted out. When the star blazes with unwonted
splendor, as in 1779, we may fairly assume that the pent-up forces of
this perishing sun have burst forth, as in a desperate struggle against
extinction. But nothing can prevail against the slow, remorseless,
unswerving progress of that obscuration, which comes from the leaking
away of the solar heat, and which constitutes what we may call the death
of a sun. And that word seems peculiarly appropriate to describe the end
of a body which, during its period of visible existence, not only
presents the highest type of physical activity, but is the parent and
supporter of all forms of life upon the planets that surround it.
We might even go so far as to say that possibly Mira presents to us an
example of what our sun will be in the course of time, as the dead and
barren moon shows us, as in a magician's glass, the approaching fate of
the earth. Fortunately, human life is a mere span in comparison with the
aeons of cosmic existence, and so we need have no fear that either we or
our descendants for thousands of generations shall have to play the
tragic _role_ of Campbell's "Last Man," and endeavor to keep up a stout
heart amid the crash of time by meanly boasting to the perishing sun,
whose rays have nurtured us, that, though his proud race is ended, we
have confident anticipations of immortality. I trust that, when man
makes his exit from this terrestrial stage, it will not be in the
contemptible act of kicking a fallen benefactor.
There are several other variable stars in Cetus, but none possessing
much interest for us. The observer should look at the group of stars in
the head, where he will find some interesting combinations, and also at
Chi, which is the little star shown in the map near Zeta ([zeta]). This
is a double that will serve as a very good test of eye and instrument,
the smaller companion-star being of only seven and a half magnitude.
Directly above Cetus is the long, straggling constellation of Pisces,
the Fishes. The Northern Fish is represented by the group of stars near
Andromeda and the Triangles. A long band or ribbon, supposed to bind the
fish together, trends thence first southeast and then west until it
joins a group of stars under Pegasus, which represents the Western Fish,
not to be confounded with the Southern Fish described near the
beginning of this chapter, which is a separate constellation. Fable has,
however, somewhat confounded these fishes; for while, as I have remarked
above, the Southern Fish is said to represent Venus after she had turned
herself into a fish to escape from the giant Typhon, the two fishes of
the constellation we are now dealing with are also fabled to represent
Venus and her interesting son Cupid under the same disguise assumed on
precisely the same occasion. If Typhon, however, was so great a brute
that even Cupid's arrows were of no avail against him, we should,
perhaps, excuse mythology for duplicating the record of so wondrous an
event.
You will find it very interesting to take your glass and, beginning with
the attractive little group in the Northern Fish, follow the windings of
the ribbon, with its wealth of tiny stars, to the Western Fish. When you
have arrived at that point, sweep well over the sky in that
neighborhood, and particularly around and under the stars Iota ([iota]),
Theta ([theta]), Lambda ([lambda]), and Kappa ([kappa]). If you are
using a powerful glass, you will be surprised and delighted by what you
see. Below the star Omega ([omega]), and to the left of Lambda, is the
place which the sun occupies at the time of the spring equinox--in other
words, one of the two crossing-places of the equinoctial or the equator
of the heavens, and the ecliptic, or the sun's path. The prime meridian
of the heavens passes through this point. You can trace out this great
circle, from which astronomical longitudes are reckoned, by drawing an
imaginary line from the equinoctial point just indicated through [alpha]
in Andromeda and [beta] in Cassiopeia to the pole-star.
To the left of Pisces, and above the head of Cetus, is the constellation
Aries, or the Ram. Two pretty bright stars, four degrees apart, one of
which has a fainter star near it, mark it out plainly to the eye. These
stars are in the head of the Ram. The brightest one, Alpha ([alpha]), is
called Hamal; Beta ([beta]) is named Sheratan; and its fainter neighbor
is Mesarthim. According to fable, this constellation represents the ram
that wore the golden fleece, which was the object of the celebrated
expedition of the Argonauts. There is not much in the constellation to
interest us, except its historical importance, as it was more than two
thousand years ago the leading constellation of the zodiac, and still
stands first in the list of the zodiacal signs. Owing to the precession
of the equinoxes, however, the vernal equinoctial point, which was
formerly in this constellation, has now advanced into the constellation
Pisces, as we saw above. Gamma ([gamma]), Arietis, is interesting as the
first telescopic double star ever discovered. Its duplicity was detected
by Dr. Hooke while watching the passage of a comet near the star in
1664. Singularly enough, the brightest star in the constellation, now
bearing the letter [alpha], originally did not belong to the
constellation. Tycho Brahe finally placed it in the head of Aries.
The little constellation of the Triangles, just above Aries, is worth
only a passing notice. Insignificant as it appears, this little group is
a very ancient constellation. It received its name, Deltoton, from the
Greek letter [Delta].
[Illustration: MAP 17.]
The reader must now be introduced to the "Royal Family." Although the
story of Perseus and Andromeda is, of course, well known to nearly all
readers, yet, on account of the great beauty and brilliancy of the group
of constellations that perpetuate the memory of it among the stars, it
is worth recalling here. It will be remembered that, as Perseus was
returning through the air from his conquest of the Gorgon Medusa, he saw
the beautiful Andromeda chained to a rock on the sea-coast, waiting to
be devoured by a sea-monster. The poor girl's only offense was that her
mother, Cassiopeia, had boasted for her that she was fairer than the
sea-beauty, Atergatis, and for this Neptune had decreed that all the
land of the Ethiopians should be drowned and destroyed unless Andromeda
was delivered up as a sacrifice to the dreadful sea-monster. When
Perseus, dropping down to learn why this maiden was chained to the
rocks, heard from Andromeda's lips the story of her woes, he laughed
with joy. Here was an adventure just to his liking, and besides, unlike
his previous adventures, it involved the fate of a beautiful woman with
whom he was already in love. Could he save her? Well, wouldn't he! The
sea-monster might frighten a kingdom full of Ethiops, but it could not
shake the nerves of a hero from Greece. He whispered words of
encouragement to Andromeda, who could scarce believe the good news that
a champion had come to defend her after all her friends and royal
relations had deserted her. Neither could she feel much confidence in
her young champion's powers when suddenly her horrified gaze met the
awful leviathan of the deep advancing to his feast! But Perseus, with a
warning to Andromeda not to look at what he was about to do, sprang with
his winged sandals up into the air. And then, as Charles Kingsley has so
beautifully told the story--
"On came the great sea-monster, coasting along like a huge black galley,
lazily breasting the ripple, and stopping at times by creek or headland
to watch for the laughter of girls at their bleaching, or cattle pawing
on the sand-hills, or boys bathing on the beach. His great sides were
fringed with clustering shells and sea-weeds, and the water gurgled in
and out of his wide jaws as he rolled along, dripping and glistening in
the beams of the morning sun. At last he saw Andromeda, and shot forward
to take his prey, while the waves foamed white behind him, and before
him the fish fled leaping.
"Then down from the height of the air fell Perseus like a
shooting-star--down to the crest of the waves, while Andromeda hid
her face as he shouted. And then there was silence for a while.
"At last she looked up trembling, and saw Perseus springing toward her;
and, instead of the monster, a long, black rock, with the sea rippling
quietly round it."
Perseus had turned the monster into stone by holding the blood-freezing
head of Medusa before his eyes; and it was fear lest Andromeda herself
might see the Gorgon's head, and suffer the fate of all who looked upon
it, that had led him to forbid her watching him when he attacked her
enemy. Afterward he married her, and Cassiopeia, Andromeda's mother, and
Cepheus, her father, gave their daughter's rescuer a royal welcome, and
all the Ethiops rose up and blessed him for ridding the land of the
monster. And now, if we choose, we can, any fair night, see the
principal characters of this old romance shining in starry garb in the
sky. Aratus saw them there in his day, more than two hundred years
before Christ, and has left this description in his "Skies," as
translated by Poste:
"Nor shall blank silence whelm the harassed house
Of Cepheus; the high heavens know their name,
For Zeus is in their line at few removes.
Cepheus himself by She-bear Cynosure,
Iasid king stands with uplifted arms.
From his belt thou castest not a glance
To see the first spire of the mighty Dragon.
"Eastward from him, heaven-troubled queen, with scanty stars
But lustrous in the full-mooned night, sits Cassiopeia.
Not numerous nor double-rowed
The gems that deck her form,
But like a key which through an inward-fastened
Folding-door men thrust to knock aside the bolts,
They shine in single zigzag row.
She, too, o'er narrow shoulders stretching
Uplifted hands, seems wailing for her child.
"For there, a woful statue-form, is seen
Andromeda, parted from her mother's side. Long I trow
Thou wilt not seek her in the nightly sky,
So bright her head, so bright
Her shoulders, feet, and girdle.
Yet even there she has her arms extended,
And shackled even in heaven; uplifted,
Outspread eternally are those fair hands.
"Her feet point to her bridegroom
Perseus, on whose shoulder they rest.
He in the north-wind stands gigantic,
His right hand stretched toward the throne
Where sits the mother of his bride. As one bent on some high deed,
Dust-stained he strides over the floor of heaven."
The makers of old star-maps seem to have vied in the effort to represent
with effect the figures of Andromeda, Perseus, and Cassiopeia among the
stars, and it must be admitted that some of them succeeded in giving no
small degree of life and spirit to their sketches.
The starry riches of these constellations are well matched with their
high mythological repute. Lying in and near the Milky-Way, they are
particularly interesting to the observer with an opera-glass. Besides,
they include several of the most celebrated wonders of the firmament.
In consulting Map No. 17, the observer is supposed to face the east and
northeast. We will begin our survey with Andromeda. The three chief
stars of this constellation are of the second magnitude, and lie in a
long, bending row, beginning with Alpha ([alpha]), or Alpheratz, in the
head, which, as we have seen, marks one corner of the great Square of
Pegasus. Beta ([beta]), or Mirach, with the smaller stars Mu ([mu]) and
Nu ([nu]), form the girdle. The third of the chief stars is Gamma
([gamma]), or Almaach, situated in the left foot. The little group of
stars designated Lambda ([lambda]), Kappa ([kappa]), and Iota ([iota]),
mark the extended right hand chained to the rock, and Zeta ([zeta]) and
some smaller stars southwest of it show the left arm and hand, also
stretched forth and shackled.
In searching for picturesque objects in Andromeda, begin with Alpheratz
and the groups forming the hands. Below the girdle will be seen a rather
remarkable arrangement of small stars in the mouth of the Northern Fish.
Now follow up the line of the girdle to the star Nu ([nu]). If your
glass has a pretty wide field, your eye will immediately catch the
glimmer of the Great Nebula of Andromeda in the same field with the
star. This is the oldest or earliest discovered of the nebulae, and, with
the exception of that in Orion, is the grandest visible in this
hemisphere. Of course, not much can be expected of an opera-glass in
viewing such an object; and yet a good glass, in clear weather and the
absence of the moon, makes a very attractive spectacle of it.
[Illustration: THE GREAT ANDROMEDA NEBULA.]
By turning the eyes aside, the nebula can be seen, extended as a faint,
wispy light, much elongated on either side of the brighter nucleus. The
cut here given shows, approximately, the appearance of the nebula,
together with some of the small stars in its neighborhood, as seen with
a field-glass. With large telescopes it appears both larger and broader,
expanding to a truly enormous extent, and in Bond's celebrated picture
of it we behold gigantic rifts running lengthwise, while the whole field
of sky in which it is contained appears sprinkled over with minute stars
apparently between us and the nebula. It was in, or, probably more
properly speaking, in line with, this nebula that a new star suddenly
shone out in 1885, and, after flickering and fading for a few months,
disappeared. That the outburst of light in this star had any real
connection with the nebula is exceedingly improbable. Although it
appeared to be close beside the bright nucleus of the nebula, it is
likely that it was really hundreds or thousands of millions of miles
either this side or the other side of it. Why it should suddenly have
blazed into visibility, and then in so short a time have disappeared, is
a question as difficult as it is interesting. The easiest way to account
for it, if not the most satisfactory, is to assume that it is a variable
star of long period, and possessing a very wide range of variability.
One significant fact that would seem to point to some connection between
star and the nebula, after all, is that a similar occurrence was noticed
in the constellation Scorpio in 1860, and to which I have previously
referred (see Chapter II). In that case a faint star projected against
the background of a nebula, suddenly flamed into comparatively great
brilliance, and then faded again. The chances against the accidental
superposition of a variable star of such extreme variability upon a
known nebula occurring twice are so great that, for that reason alone,
we might be justified in thinking some mysterious causal relation must
in each case exist between the nebula and the star. The temptation to
indulge in speculation is very great here, but it is better to wait for
more light, and confess that for the present these things are
inexplicable.
It will be found very interesting to sweep with the glass slowly from
side to side over Andromeda, gradually approaching toward Cassiopeia or
Perseus. The increase in the richness of the stratum of faint stars that
apparently forms the background of the sky will be clearly discernible
as you approach the Milky-Way, which passes directly through Cassiopeia
and Perseus. It may be remarked that the Milky-Way itself, in that
splendidly rich region about Sagittarius (described in the "Stars of
Summer"), is not nearly so effective an object with an opera-glass as it
is above Cygnus and in the region with which we are now dealing. This
seems to be owing to the smaller magnitude of its component stars in the
southern part of the stream. There the background appears more truly
"milky," while in the northern region the little stars shine distinct,
like diamond-specks, on a black background.
The star Nu, which serves as a pointer to the Great Nebula, is itself
worth some attention with a pretty strong glass on account of a pair of
small stars near it.
The star Gamma ([gamma]) is interesting, not only as one of the most
beautiful triples in the heavens (an opera-glass is far too feeble an
instrument to reveal its companions), but because it serves to indicate
the radiant point of the Biela meteors. There was once a comet well
known to astronomers by the name of its discoverer, Biela. It repeated
its visits to the neighborhood of the sun once in every six or seven
years. In 1846 this comet astonished all observers by splitting into two
comets, which continued to run side by side, like two equal racers, in
their course around the sun. Each developed a tail of its own. In 1852,
when the twin comets were due again, the astronomical world was on the
_qui vive_, and they did not disappoint expectation, for back they came
out of the depths of space, still racing, but much farther apart than
they had been before, alternating in brightness as if the long struggle
had nearly exhausted them, and finally, like spent runners, growing
faint and disappearing. They have never been seen since.
In 1872, when the comets should have been visible, if they still
existed, a very startling thing happened. Out of the northern heavens,
along the track of the missing comets, where the earth crossed it, on
the night of the 27th of November came glistening and dashing the fiery
spray of a storm of meteors. It was the dust and fragments of the lost
comet of Biela, which, after being split in two in 1852, had evidently
continued the process of disintegration until its cometary character was
completely lost. It seems to have made a truly ghostly exit, for right
after the meteor swarm of 1872 a mysterious cometary body was seen,
which was supposed at the time to be the missing comet itself, and
which, it is not altogether improbable, may have been a fragment of it.
Three days after the meteors burst over Europe, it occurred to Professor
Klinkerfues, of Berlin, that if they came from Biela's comet the comet
itself ought to be seen in the southern hemisphere retreating from its
encounter with the earth. On November 30th he sent his now historical
telegram to Mr. Pogson, an astronomer at Madras; "Biela touched earth
November 27th. Search near Theta Centauri." For thirty-six hours after
the receipt of this extraordinary request Mr. Pogson was prevented by
clouds from scanning the heavens with his telescope. When the sky
cleared at last, behold there was a comet in the place indicated in the
telegram! It was glimpsed again the next night, and then clouds
intervened, and not a trace of it was ever seen afterward.
But every year, on the 27th of November, when the earth crosses the
orbit of the lost comet, meteoric fragments come plunging into our
atmosphere, burning as they fly. Ordinarily their number is small, but
when, as in 1872, a swarm of the meteors is in that part of their orbit
which the earth crosses, there is a brilliant spectacle. In 1885 this
occurred, and the world was treated to one of the most splendid meteoric
displays on record.
[Illustration: THE ATTENDANTS OF ALPHA PERSEI.]
Next let us turn to Perseus. The bending row of stars marking the center
of this constellation is very striking and brilliant. The brightest star
in the constellation is Alpha, or Algenib, in the center of the row. The
head of Perseus is toward Cassiopeia, and in his left hand he grasps the
head of Medusa, which hangs down in such a way that its principal star
Beta, or Algol, forms a right angle with Algenib and Almaach in
Andromeda. This star Algol, or the Demon, as the Arabs call it, is in
some respects the most wonderful and interesting in all the heavens. It
is as famous for the variability of its light as Mira, but it differs
widely from that star both in its period, which is very short, and in
the extent of the changes it undergoes. During about two days and a
half, Algol is equal in brilliance to Algenib, which is a
second-magnitude star; then it begins to fade, and in the course of
about four and a half hours it sinks to the fourth magnitude, being then
about equal to the faint stars near it. It remains thus obscured for
only a few minutes, and then begins to brighten again, and in about four
and a half hours more resumes its former brilliance. This phenomenon is
very easily observed, for, as will be seen by consulting our little map,
Algol can be readily found, and its changes are so rapid that under
favorable circumstances it can be seen in the course of a single night
to run through the whole gamut. Of course, no optical instrument
whatever is needed to enable one to see these changes of Algol, for it
is plainly visible to the naked eye throughout, but it will be found
interesting to watch the star with an opera-glass. Its periodic time
from minimum to minimum is two days, twenty hours, and forty-nine
minutes, lacking a few seconds. Any one can calculate future minima for
himself by adding the periodic time above given to the time of any
observed minimum.
While spots upon its surface may be the cause of the variations in the
light of Mira, it is believed that the more rapid changes of Algol may
be due to another cause; namely, the existence of a huge, dark body
revolving swiftly around it at close quarters in an orbit whose plane is
directed edgewise toward the earth, so that at regular intervals this
dark body causes a partial eclipse of Algol. Notwithstanding the attacks
that have been made upon this theory, it seems to hold its ground, and
it will probably continue to find favor as a working hypothesis until
some fresh light is cast upon the problem. It hardly needs to be said
that the dark body in question, if it exists, must be of enormous size,
bearing no such insignificant proportion to the size of Algol as the
earth does to the sun, but being rather the rival in bulk of its shining
brother--a blind companion, an extinguished sun.
There was certainly great fitness in the selection of the little group
of stars of which this mysterious Algol forms the most conspicuous
member, to represent the awful head of the Gorgon carried by the
victorious Perseus for the confusion of his enemies. In a darker age
than ours the winking of this demon-star must have seemed a prodigy of
sinister import.
Turn now to the bright star Algenib, or Alpha Persei. You will find with
the glass an exceedingly attractive spectacle there. In my note-book I
find this entry, made while sweeping over Perseus for materials for this
chapter: "The field about Alpha is one of the finest in the sky for an
opera-glass. Stars conspicuously ranged in curving lines and streams. A
host follows Alpha from the east and south." The picture on page 84 will
give the reader some notion of the exceeding beauty of this field of
stars, and of the singular manner in which they are grouped, as it were,
behind their leader. A field-glass increases the beauty of the scene.
The reader will find a starry cluster marked on Map 17 as the "Great
Cluster." This object can be easily detected by the naked eye,
resembling a wisp of luminous cloud. It marks the hand in which Perseus
clasps his diamond sword, and, with a telescope of medium power, it is
one of the most marvelously beautiful objects in the sky--a double swarm
of stars, bright enough to be clearly distinguished from one another,
and yet so numerous as to dazzle the eye with their lively beams. An
opera-glass does not possess sufficient power to "resolve" this cluster,
but it gives a startling suggestion of its half-hidden magnificence, and
the observer will be likely to turn to it again and again with
increasing admiration. Sweep from this to Alpha Persei and beyond to get
an idea of the procession of suns in the Milky-Way. The nebulous-looking
cluster marked 34 M appears with an opera-glass like a faint comet.
About a thousand years ago the theologians undertook to reconstruct the
constellation figures, and to give them a religious significance. They
divided the zodiac up among the twelve apostles, St. Peter taking the
place of Aries, with the Triangles for his mitre. In this reconstruction
Perseus was transmogrified into St. Paul, armed with a sword in one hand
and a book in the other; Cassiopeia became Mary Magdalene; while poor
Andromeda, stripped of all her beauty and romance, was turned into a
sepulchre!
Next look at Cassiopeia, which is distinctly marked out by the zigzag
row of stars so well described by Aratus. Here the Milky-Way is so rich
that the observer hardly needs any guidance; he is sure to stumble upon
interesting sights for himself. The five brightest stars are generally
represented as indicating the outlines of the chair or throne in which
the queen sits, the star Zeta ([zeta]) being in her head. Look at Zeta
with a good field-glass, and you will see a singular and brilliant array
of stars near it in a broken half-circle, which may suggest the notion
of a crown. Near the little star Kappa ([kappa]) in the map will be seen
a small circle and the figures 1572. This shows the spot where the
famous temporary star, which has of late been frequently referred to as
the "Star of Bethlehem," appeared. It was seen in 1572, and carefully
observed by the famous astronomer Tycho Brahe. It seems to have suddenly
burst forth with a brilliance that outshone every other star in the
heavens, not excepting Sirius itself. But its supremacy was short-lived.
In a few months it had sunk to the second magnitude. It continued to
grow fainter, exhibiting some remarkable changes of color in the mean
time, and in less than a year and a half it disappeared. It has never
been seen since. But in 1264, and again in 945, a star is said to have
suddenly blazed out near that point in the heavens. There is no
certainty about these earlier apparitions, but, assuming that they are
not apocryphal, they might possibly indicate that the star seen by Tycho
was a periodical one, its period considerably exceeding three hundred
years. Carrying this supposed period back, it was found that an
apparition of this star might have occurred about the time of the birth
of Christ. It did not require a very prolific imagination to suggest its
identity with the so-called star of the Magi, and hence the legend of
the Star of Bethlehem and its impending reappearance, of which we have
heard so much of late. It will be observed, from the dates given above,
that, even supposing them to be correct, no definite period is indicated
for the reappearance of the star. In one case the interval is three
hundred and eight years, and in the other three hundred and nineteen
years. In short, there are too many suppositions and assumptions
involved to allow of any credence being given to the theory of the
periodicity of Tycho's wonderful star. At the same time, nobody can say
it is impossible that the star should appear again, and so it may be
interesting for the reader to know where to look for it.
Many of the most beautiful sights of this splendid constellation are
beyond the reach of an opera-glass, and reserved for the grander powers
of the telescope.
We will pause but briefly with Cepheus, for the old king's constellation
is comparatively dim in the heavens, as his part in the dramatic story
of Andromeda was contemptible, and he seems to have got among the stars
only by virtue of his relationship to more interesting persons. He does
possess one gem of singular beauty--the star Mu, which may be found
about two and a half degrees south of the star Nu ([nu]). It is the
so-called "Garnet Star," thus named by William Herschel, who advises the
observer, in order to appreciate its color, to glance from it to Alpha
Cephei, which is a white star. Mu is variable, changing from the fourth
to the sixth magnitude in a long period of five or six years. Its color
is changeable, like its light. Sometimes it is of a deep garnet hue, and
at other times it is orange-colored. Upon the whole, it appears of a
deeper red than any other star visible to the naked eye.
If you have a good field-glass, try its powers upon the star Delta
([delta]) Cephei. This is a double star, the components being about
forty-one seconds of arc apart, the larger of four and one half
magnitude, and the smaller of the seventh magnitude. The latter is of a
beautiful blue color, while the larger star is yellow or orange. With a
good eye, a steady hand, and a clear glass, magnifying not less than six
diameters, you can separate them, and catch the contrasted tints of
their light. Besides being a double star, Delta is variable.