THE PHENOMENA OF THE STARS.
Let us now consider the phenomena of the double stars. These
were formerly believed to be single orbs, but the more powerful
telescopes of recent years have shown them to consist of two suns,
each substantially similar to our own sun, revolving around each
other at a relatively small distance apart. In Appleton's Cyclopædia,
article "Star," we read, "It is noteworthy that few simple stars
show such colors as blue, green, violet, or indigo; but among double
and multiple star systems not only are these colors recognized, but
such colors as lilac, olive, gray, russet, and so on. A beautiful
feature in many double stars remains to be noticed: it is often found
that the components exhibit complementary colors. This is oftener
seen among unequal doubles, and then the larger component shows a
color from the red end of the spectrum, as red, orange, or yellow,
while the smaller shows the corresponding color from the blue end,
as green, blue, or purple. The colors are real, not merely the result
of contrast, for when the larger star is concealed the color of the
smaller remains (in most cases) unchanged. Spectrum analysis shows
that the colors of many double stars are due to the absorptive vapors
cutting off certain portions of the light.... The components are
circling around each other, or rather around their common center of
gravity." Professor Ball, in his work "In the High Heavens," says,
"There is no more pleasing phenomenon in sidereal astronomy than
that presented by the contrasted hues often exhibited by double
stars.... It seemed not at all impossible that there might be some
optical explanation of colors so vividly contrasted emanating from
points so contiguous. It was also remembered that blue stars were
generally only present as one member of an associated pair.... When,
however, Dr. Huggins showed that the actual spectrum of the object
demonstrated that the cause of the color in each star arose from
absorption by its peculiar atmosphere, it became impossible to doubt
the reality of the phenomena. Since then it has been for physicists
to explain why two closely neighboring stars should differ so widely
in their atmospheric constituents, for it can be no longer contended
that their beautiful hues arise from an optical illusion."
Of these double stars with complementary colors we quote the following
from Professor Dunkin (who, in turn, quotes from Admiral Smyth, the
author of "Sidereal Chromatics"): "In Eta Cassiopeiæ the large star
is a dull white and the smaller one lilac; in Gamma Andromedæ, a deep
yellow and sea-green; in Iota Cancri, a dusky orange and a sapphire
blue; in Delta Corvi, a bright yellow and purple; and in Albiero,
or Beta Cygni, yellow and blue. In most of the remaining stars of
the list the contrasting colors are equally marked, and also in many
others which are not included in it." Some of these double stars are
variable in their colors, as are the ordinary single variables, and,
of course, for a similar reason,--to wit, the varying intensity of
more or less cumulative planetary impacts.
The interpretation, of course, as explained below, is that these suns,
each one of different mass and consequently of different electrical
resistance, are arranged in parallel circuit along a single line of
electric current; a pair of different-sized arc or incandescent lamps,
similarly arranged, would exhibit precisely the same phenomena. A
compound solar system of this sort, apparently, with double sun and
single planetary system in process of formation, nearly completed
from a spiral nebula, is shown in a gaseous nebula within the
constellation Ursa Minor, illustrated in Lord Rosse's drawing (see
Nichols "Architecture of the Heavens," Plate X., lower figure).
More than three thousand of these binary stars have been catalogued,
and some of them make a complete revolution about their common
centers of gravity--so distant are they from each other--in periods
of not less than sixty, or even eighty, years. Of the double star
Mizar,--the middle one of the three which form the tail of the Great
Bear,--Professor Ball states that, by new methods of spectroscopic
analysis, the component stars which form this double have been found
to be one hundred and fifty millions of miles apart, while Alcor, a
smaller star, visible to the naked eye, and enormously farther from
Mizar than are the components of the latter from each other, moves
through space in a parallel direction and with the same velocity as
its double companion. What the connection may be, if any, we do not
know, but their identical course is obviously related to some common
circumstance of origin, as is the probable case with those other
groups of stars which drift through space together. They show that
solar systems are not necessarily individual creations, but may be
formed in groups at the same period of time, and by the operation of
natural laws simultaneously directed upon or into the creative matter
from which solar systems are built up and sent along their way. It
has been already shown that our sun has a motion around the center
of gravity of our own solar system, as a whole, similar to that of
the binary stars around each other, but that, by reason of his vast
relative mass (seven hundred and fifty to one for all the planets),
this center is always within the confines of his own volume. If,
however, our sun were divided into two suns one, two, or five million
miles apart, each revolving around a common center of gravity situated
between the two, and the planets revolving around the same center
of gravity, but relatively more distant, the planets would thus
rotate around both suns as a common center, and with the electric
polarity of both suns the same, as must necessarily be the case,
they would present phenomena precisely similar to those exhibited by
the double stars. And such might very easily be the case in even a
system so small as our own, for the planet Mercury has so elliptical
an orbit that its distance from the sun varies in different parts
of its annual movement from twenty-eight to forty-five millions
of miles. There would then be mutual electric repulsion of the two
solar electrospheres, such as we see in the case of comets and in
the sun's corona and long streamers. Professor Proctor, article
"The Sun's Long Streamers," says, "These singular appendages, like
the streamers seen by Professor Abbe, extend directly from the sun,
as if he exerted some repellent action.... I cannot but think that
the true explanation of these streamers, whatever it may be (I am not
in the least prepared to say what it is), will be found whensoever
astronomers have found an explanation of comets' tails.... Whether
the repulsive force is electrical, magnetic, or otherwise, does not
at present concern us, or rather does concern us, but at present we
are quite unable to answer the question." A similar example is to
be found in the self-repellent positive electrospheres of the earth
and moon, illustrated on a previous page, which, in fact, are types
among planets of precisely what we find in double stars. Now, if
these double central suns, with a common system of planets revolving
around them both, differ one from the other in size, they will differ
also in the depth and density of their hydrogen atmospheres, and the
electric forces directed against them will produce different results
in each. In one we will have high temperature, great volatilization,
and wide absorption bands; in the other, a shallow atmosphere,
a temperature below that of an extensive volatilization of its
metallic components, and a spectrum rich in light at the blue end,
while the former one will be correspondingly richer in the yellow
and red rays at the opposite and lower end of the spectrum. One,
in fact, will manifest the phenomena of blue-white stars, the other,
those of orange-red, but variously modified in a chromatic series. The
case may be extended to multiple stars, and complementary colors,
more or less perfect, may be almost predicated as the law of compound
solar bodies having cores like that of our sun, but each of different
mass, and surrounded by hydrogen atmospheres of different depths and
densities, both acted upon by the same exterior planetary electrical
currents. It is certainly true of double stars, and probably so of all
the others. Of course such enormously massive double suns presuppose
enormous planets, rotating around them at enormous distances; but
when we compare the distance of our own satellite, the moon, from
the earth with the distance of Neptune from the sun, and consider
that the light of the sun will reach Neptune in about four hours, and
then compare this distance with the inconceivable distances of space
requisite to retard and merge all radiant energy into the diffused
molecular energy of position, our wonder will cease.
We have also to consider those single stars which (see Appleton's
Cyclopædia, article "Star") are variable in their brilliancy. "These
stars may be divided into periodic variables, irregular variables,
and temporary stars. Periodic variable stars are those which undergo
increase and diminution of light at regular intervals. Thus, the
star Mira, or Omicron of Cetus, varies in lustre, in a period of
three hundred and thirty-one and one-third days, from the second
magnitude to a faintness such that the star can only be seen with
a powerful telescope, and thence to the second magnitude again. It
shines for about a fortnight as a star of the second magnitude,
and then remains invisible for five months, the decrease of lustre
occupying about three months, the increase about seven weeks. Such
is the general course of its phases. It does not always, however,
return to the same degree of brightness, nor increase and diminish
by the same gradations; neither are the successive intervals of its
maxima equal. From recent observations and inquiries into its history,
the mean period would appear to be subject to a cyclical fluctuation
embracing eighty-eight such periods, and having the effect of gradually
lengthening and shortening alternately those intervals to the extent
of twenty-five days one way and the other. The irregularities in
the degree of brightness attained at the maximum are probably also
periodical.... It suggests a probable explanation of these changes of
brightness, that when the star is near its minimum, its color changes
from white to a full red, which, from what we know of the spectra of
colored stars, seems to indicate that the loss of brightness is due
to the formation of many spots over the surface of this distant sun.
"Algol is another remarkable variable, passing, however, much more
rapidly through all its changes. It is ordinarily a second-magnitude
star, but during about seven hours in each period of sixty-nine hours
its lustre first diminishes until the star is reduced to a fourth
magnitude, and after it has remained twenty minutes at its minimum its
lustre is gradually restored. It remains a second-magnitude star for
about sixty-two hours in each period of sixty-nine hours. These changes
seem to correspond to what might be expected if a large opaque orb
is circling around this distant sun in a period of sixty-nine hours,
transiting its disk at regular intervals."
Of this star, Professor Ball says, "Applying the improved spectroscopic
process to Algol, he [Vogel] determined on one night that Algol
was retreating from the earth at a speed of twenty-six miles per
second.... When Vogel came to repeat his observations, he found that
Algol was again moving with the same velocity, but this time towards
the earth instead of from it.... It appeared that the movements were
strictly periodic; that is to say, for one day and ten hours the star
is moving towards us, and then for a like time it moves from us, the
maximum speed being ... twenty-six miles a second.... It is invariably
found that every time the movement of retreat is concluded the star
loses its brilliance, and regains it again at the commencement of the
return movement.... The spectroscopic evidence admits of no other
interpretation save that there must be another mighty body in the
immediate vicinity of Algol.... Algol must be attended by a companion
star which, if not absolutely as devoid of intrinsic light as the
earth or the moon, is nevertheless dark relatively to Algol. Once in
each period of revolution this obscure body intrudes itself between
the earth and Algol, cutting off a portion of the direct light from
the star and thus producing the well-known effect." This is, in fact,
a periodic transit or eclipse of Algol by a planet, such as we see in
eclipses of our own sun by the moon and the inner planets, except that
Algol's planet is apparently single like our moon with reference to
the earth, and that it is relatively much larger than any of our own
planets, as we would necessarily suppose it to be, if solitary. Its
mass has been computed by the effects which it produces, and we learn
that it is not a dark sun with a brilliant planet, but a brilliant
sun with a dark planet, just as our solar system presents. "Algol,
at the moment of its greatest eclipse, has lost about three-fifths
of its light; it therefore follows that the dark satellite must have
covered three-fifths of the bright surface.... The period of maximum
obscuration is about twenty minutes, and we know the velocity of the
bright star, which, along with the period of revolution, gives the
magnitude of the orbit." From these data it has been computed that
the globe of Algol itself is about one-fourth larger than that of
our visible sun, but its mass is so much less that its weight is only
one-half that of our sun, so that its body is probably gaseous. The
author concludes, "No one, however, will be likely to doubt that it
is the law of gravitation, pure and simple, which prevails in the
celestial spaces, and consequently we are able to make use of it to
explain the circumstances attending the movements of Algol's dark
companion. This body is the smaller of the two, and the speed with
which it moves is double as great as that of Algol, so that it travels
over as many miles in a second as an express train can get over in an
hour. The companion of Algol is about the same size as our sun, but
has a mass only one-fourth as great. This indicates a globe of matter
which must be largely in the gaseous state, but which, nevertheless,
seems to be devoid of intrinsic luminosity. Their distance [apart]
is always some three million miles. This is, however, an unusually
short distance when compared with the dimensions of the two globes
themselves." With this exception, the author says, "the movements of
Algol and its companion are not very dissimilar to movements in the
solar system with which we are already familiar." It will be seen that
the want of luminosity in the dark companion of Algol finds a ready
explanation in the fact that it is a planet, acting precisely as our
own planets do, and that the luminosity of Algol itself is directly
attributable to the electricity developed by the presence of this
planet rotating axially and orbitally around it, and the darkness of
the planet itself is the necessary correlative of the heat and light
of its sun. The planet has about one-half the density of Saturn, while
Algol has one-half the density of the sun, and hence we should expect
to find on Algol an atmosphere largely composed of glowing hydrogen,
and on its planet an atmosphere largely composed of oxygen, in which,
doubtless, float enormous clouds of aqueous vapor. The interpretation
is direct and conclusive, and upon no other hypothesis can the facts
be explained, for their close connection with each other demonstrates
their common origin, and their masses are not so different one from the
other as to permit, on any theory of their coequal origin as suns, one
to glow with the fires of youth and energy and the other to have grown
dark and dead from old age and exhaustion, and especially so if still
in its gaseous stage, which is that which must characterize its highest
state of incandescent energy from the most active condensation of its
volume, if the nebular hypothesis has any validity whatever. In fact,
this example alone, if the constitution of Algol's dark satellite is
really gaseous, must go very far to throw the gravest doubt, in itself,
on the validity of this hypothesis.
The star Beta, of the constellation Lyra, has a full period of twelve
days and twenty-two hours, divided into two periods of six days and
eleven hours, in each of which the star has a maximum brightness of
about the three and one-half magnitude, but in one period the minimum
is about the four and one-third magnitude, while in the other it
is about the four and one-half magnitude. This peculiarity points,
it is said, to an opaque orb with a satellite, the satellite being
occulted by the primary in the alternative transits, and therefore
the loss of light is less.
The star Delta of Cepheus is quite different, however, for, while it
takes only one, day and fourteen hours in passing from its minimum
to maximum of brightness, it occupies three days and nineteen hours,
or somewhat more than double this time, in passing from maximum to
minimum. Two or three hundred of these variable stars are already
known. The above examples are cited in detail because they furnish
the strongest possible proof of the truth of the hypothesis which we
are endeavoring to present. While the movements of the stars Algol
and Beta Lyræ may find an adequate interpretation in the one case
in a large occulting planet, and in the other in an occulting planet
with a satellite, it is obvious that Mira and Delta Cephei cannot be
explained except by the presence of planetary bodies or satellites
which do not mechanically occult the light of their suns. In these
regularly variable stars it is the light which varies, but of course
the solar heat must vary also,--that is to say, the solar energy varies
regularly, but with unequal periods of growth and decline and with
larger periods of cyclical variation in addition. Such variations can
only be produced by the action of permanently connected and orbitally
rotating planetary bodies, acting dynamically through space, to
regularly increase and diminish the solar energy, and such bodies can
only do this by their orbital positions with reference to each other
and to the central sun itself. In this case, since the activity of
solar energy is most unquestionably varied by the planetary energies,
by their position and movements, at least a portion of solar energy
must be due to planetary action, and if this be so, it may be affirmed
with certainty that substantially all solar energy may be produced in
the same way; for, otherwise, we seek for two diverse causes to produce
a single effect, which may be produced by one. We have no knowledge,
however, of any planetary energy which could operate to increase or
diminish the energy of the central sun in its emission of light, except
that which we have already presented, and no theory of our own sun's
energy hitherto advanced has ever taken cognizance of the planetary
energies of our system as an effective cause for those of the sun. But
while the sun's energy is--as it must be in this case--the outcome of
that of the planets, it is equally obvious that the planets themselves
can have no permanent, inherent energy of their own to generate or
modify such energy of the sun, since they are in fact supplied by
the solar energy, and their motions are controlled and regulated by
the sun itself. Hence the inference is irresistible that the planets
must derive their primary force from an external source not solar,
and this they can only do by means of their rotation in space, and
the only force derivable from space of which we have any knowledge
is electricity, so that the circle thus becomes complete. How now
shall we explain these periodical aberrations of energy? The color
of a star, as we know, is no criterion of its age or size. The color
is due to atmospheric absorption of the radiant light. The double
stars, for example, revolve around each other at regular periods,
and they are necessarily of nearly the same age, as sidereal ages
are computed, but they frequently differ one from the other in color,
and multiple stars may be all different each from the others; and the
color, as before stated, is no criterion of size, for a small sun,
with its glowing hydrogen in a state of high incandescence, and with
few absorption bands in its spectrum, will appear bluish-white, or of
that specific type of stars, without reference to size, while a much
larger sun, with its light darkened by broad absorption bands and
sun-spots, will appear orange or red; and, consequently, difference
of color can be no criterion of distance, since a blue-white star of
small size will outshine a red orb of much greater magnitude, whether
it be more or less distant. The variable stars, for these reasons,
belong to the order of red stars mostly, if not altogether. We must
also bear in mind that sun-spots do not diminish the solar heat, as
they are the result of increased and not of diminished energy. Electric
currents of high potential pass directly, as we know, along the lines
of least resistance to their opposite center of polarity, so that two
planets nearly in conjunction with each other transmit their currents
almost directly towards the sun's center, and upon the same point
of solar latitude, while, if at right angles with the sun, they must
deliver their electricity along converging lines and thus strike the
solar surface at different points. Currents of electricity of high
potential also (see "Electricity in the Service of Man," page 75),
by their own passage, facilitate the passage of succeeding currents,
so that generators discharging along the same lines find less and
less resistance. It is true that we find no appreciable resistance
in the passage of these currents between the earth and the sun, as
their velocity is that of light, but both light and electricity may
be equally retarded by resistance in a small degree. We know also
that in the condensed hydrogen atmosphere of the sun there must be
resistance, and also that the resistance in fluids diminishes as the
temperature rises. Considering now the variable star Mira, as above
described, we observe, as is the case with Delta Cephei, also cited,
that the period between its greatest light, in a descending scale,
and its least is about twice as long as its rise from minimum to
maximum. During a period of four years (1672 to 1676) it is said that
it was not visible at all.
If Mira be considered a relatively small sun, with its axis strongly
inclined to the planetary plane, and having three planets only, two of
them constituting a double planet, like the earth and moon, but nearly
equal in size, and having a rotation about the sun in nearly eleven
months and a rotation about each other in the same period, and, besides
these, a much more distant large planet, something like our Jupiter,
with an orbital period of many years, so that the cycle of relative
positions is complete in about eighty-eight of the shorter periods of
variation, we would have such results as we see in Mira. Twice in each
revolution of the double planet its two members and their sun would be
in conjunction, and we would have great brilliancy and whiteness until
the metallic elements began to volatilize in increased proportions;
then an era of wide absorption bands and redness, gradually increasing
to a maximum after its periods of greatest light, and then slowly
diminishing as the double planet advanced in its rotation; and,
finally, as it again approached conjunction, the brilliant hydrogen
illumination, subsequently followed by the gradually darkened spectrum,
and so on, while the large outer planet by its various positions
would first relatively retard and then accelerate the variation
until its grand cycle was complete. The permanent disappearance for
years, if true, may be due to other causes, which will be referred
to in considering the phenomena of new and temporary stars. Many of
the irregular variables may doubtless be similarly explained,--our
own sun, in fact, being a variable with a period of about eleven
years,--and doubtless the apparent irregularity in most cases is
due to lack of sufficient time for observation. Those stars which
are in fact really irregular in their variation owe their changes,
doubtless, to the same causes which produce new stars, so called,
and "suns in flames," which will be next considered.
Among the countless stars of heaven a great catastrophe seems
occasionally to occur. A star bursts out into sudden flame, to all
appearance, or a great fixed star appears where no star had ever been
seen before. In Professor Proctor's article, "Suns in Flames" ("Myths
and Marvels of Astronomy"), we will find an extended discussion of
these wonderful phenomena. The astronomer Tycho Brahe described the
one which appeared in 1572 as follows: "It suddenly shone forth in
the constellation Cassiopeia with a splendor exceeding that of stars
of the first magnitude, or even Jupiter or Venus at their brightest,
and could be seen by the naked eye on the meridian at full day. Its
brilliancy gradually diminished from the time of its first appearance,
and at the end of sixteen months it entirely disappeared, and has never
been seen since. During the whole time of its apparition its place in
the heavens remained unaltered, and it had no annual parallax, so that
its distance was of the same order as that of the fixed stars." Tycho
described its changes of color as follows: first, as having been of a
bright white; afterwards of a reddish-yellow, like Mars or Aldebaran;
and, lastly, of a leaden white, like Saturn. In 1604 a first-magnitude
star suddenly appeared in the right foot of Ophiucus. "It presented
appearances resembling those shown by the former, and disappeared
after a few months." Many other cases are cited by astronomers, and
in 1866 "a star appeared in the Northern Crown, the observations of
which threw great light on the subject of so-called new stars. In
the first place, it was found that where this new star appeared there
had been a tenth-magnitude star; the new star, then, was in reality
a star long known, which had acquired new brilliancy. "When first
observed with this abnormal lustre, it was shining as a star of the
second magnitude. Examined with the spectroscope, its light revealed a
startling state of things in those remote depths of space. The usual
stellar spectrum, rainbow-tinted and crossed by dark lines, was seen
to be crossed also by four exceedingly bright lines, the spectrum of
glowing hydrogen.... The greater part of the star's light manifestly
came from this glowing hydrogen, though it can scarcely be doubted
that the rest of the spectrum was brighter than before the outburst,
the materials of the star being raised to an intense heat. The maximum
brightness exceeded that of a tenth-magnitude star nearly eight hundred
times. After shining for a short time as a second-magnitude star,
it diminished rapidly in lustre, and it is now between the ninth
and tenth magnitudes" (Appleton's Cyclopædia). Of this new star,
Professor Ball says, "Another memorable achievement in the early part
of Dr. Huggins's career is connected with the celebrated new star that
burst forth in the Crown in 1866. It seemed a fortunate coincidence
that just at the moment when the spectroscope was beginning to be
applied to the sidereal heavens a star of such marvellous character
should have presented itself.... The feature which made the spectrum
of the new star essentially distinct from that of any other star
that had been previously observed was the presence of certain bright
lines superposed on a spectrum with dark lines of one of the ordinary
types. The position of certain of these lines showed that one of the
luminous gases must be hydrogen.... The spectroscope showed that there
must have been something which we may describe as a conflagration
of hydrogen on a stupendous scale, and this outburst would account
for the sudden increase in luminosity of the star, and also to some
extent explain how so stupendous an illumination, once kindled, could
dwindle away in so short a time as a few days." It will be seen that
these new stars leap suddenly into great brilliancy: it is a matter
of a few hours only. After remaining a very short time in this stage
of abnormal incandescence, they gradually die out again in lustre and
revert to their original condition; they are not consumed either in
body or atmosphere.
Several theories have been advanced to account for these remarkable
phenomena; see "Suns in Flames," by Professor Proctor. One is, in
effect, that by some sudden "internal convulsion a large volume of
hydrogen and other gases was evolved from it, the hydrogen by its
combination with some other element giving out the lines represented
by the bright lines, and at the same time heating to a point of
vivid incandescence the solid matter of the star's surface.... As the
liberated hydrogen gas became exhausted the flame gradually abated,
and with the consequent cooling the star's surface became less vivid
and the star returned to its original condition;" which, by the way,
it never could have done if its atmosphere had been exposed to such a
disintegration, without the construction of an entirely new atmosphere
precisely similar to the one just destroyed. The process would be one
of simple combustion. It requires the evolution of enormous volumes
of hydrogen from within the planet, and of other enormous volumes of
something else, by which to burn it up and yet not burn up the original
hydrogen envelope. This other element could not have previously
existed outside the solar body and contiguous thereto, or it would
have burned up the ordinary hydrogen envelope of the sun long before,
as well as the metallic vapors floating therein. Both these mutually
hostile gases must have come from within, and this is manifestly
impossible, as we should thus have explosion and solar destruction,
but not combustion. There is no reason to believe that hydrogen,
the lightest of elements, could have remained occluded within the
solar mass, to the exclusion of the heavier metals, if disassociated,
and if held combined no such sudden liberation could occur. Besides,
such convulsion would be impossible in any sun at all resembling ours,
as any further liberation of gases from internal condensation must be
due to solar contraction, hence gradual, and not sudden. Moreover,
such liberation of hydrogen gas from within would show its spectrum
loaded, at its earliest eruption, with absorption bands; and, finally,
the convulsion presupposes as great an activity, and consequently as
great a difficulty, before the phenomenon as the phenomenon itself
presents; for such vast disturbance of mass would be more difficult
to account for, and require more energy to produce, than the results
themselves. Moreover, the whole mass of the star appeared to increase
equally in temperature, as shown by the spectrum, and, if produced by
an internal convulsion, this must have extended to, if not proceeded
from, its core; so that while the combustion of hydrogen might have
ceased in a very brief time, the intense heat of the solar mass could
not have been dissipated for thousands of years. It would, in fact,
have disrupted the whole orb.
Another theory is that this vast incandescence was caused by the
"violent precipitation of some mighty mass--perhaps a planet--upon
the globe of that remote sun, by which the momentum of the falling
mass would be changed into molecular motion; in other words, into
heat and light." This theory is no more plausible than the other,
since it fails to account for the enormous volume of hydrogen, with
bright lines, as a result of such contact; while Professor Proctor
very clearly shows that such contact would have been preceded,
necessarily, by repeated partial grazings, as the outside body
repeatedly passed in swifter and closer passage by the sun in its
gradually approaching orbital revolutions, and that the increase
of light and heat must have been measured by years instead of by
hours. The same difficulties exist in the supposed passage of the star
through nebulæ or star clouds, of which Professor Proctor says, "As
for the rush of a star through a nebulous mass, that is a theory which
would scarcely be entertained by any one acquainted with the enormous
distances separating them.... All we certainly know suggests that the
distances separating them from each other are comparable with those
which separate star from star." In fact, no tenable theory has been
advanced which will cover the phenomena. Professor Proctor describes
a star which flamed out in 1876. At midnight, November 24, a star
of the third magnitude was noticed in the constellation of the Swan;
its light was very yellow; its brilliancy rapidly faded. On December
2 it was equal to a star of the fifth magnitude only, and the color,
which had been yellow, was now greenish-blue. "The star's spectrum
at this time consisted almost entirely of bright lines. December 5 he
found three bright lines of hydrogen, the strong double line of sodium,
the triple line of magnesium, and two other lines. One of these last
seemed to agree exactly in position with a bright line belonging
to the corona seen around the sun during total eclipse." The star
afterwards faded away gradually until quite invisible to the naked
eye. It will be noticed that none of the above elements--sodium,
potassium, or magnesium--are such as would combine with hydrogen
to produce the phenomena in question. Professor Proctor concludes,
"This evidence seems to me to suggest that the intense heat which
suddenly affected this star had its origin from without." He suggests
possible meteoric flights; but meteoric stones themselves are separated
in space by enormous distances, and these, if converged in orbital
flight, would present the same phenomena of successive grazings as
a small planet approaching under like circumstances, and by their
gradually increasing incandescence we should certainly have other
elements visible in the spectroscope besides those observed. And these
meteoric bodies, if projected into the sun, would pass in a very brief
time through the hydrogen envelope, producing only local phenomena,
so that their first blow would be manifested in volatilization of the
outer portions of the mass and broad absorption bands, and consequent
redness of the planet, exhibiting great heat, but not great light. In
such case the bright lines of hydrogen, if they appeared at all, would
only be visible as an after-consequence, and not at the earliest moment
of conflagration,--that is, the star might grow from red to white,
but by no possibility the reverse. It is, however, characteristic
of these new stars that their first flash, as it were, is into the
incandescence of directly glowing hydrogen, with its bright lines,
then through a series of gradually increasing sun-spots, and finally
a slow return to their original condition and apparent magnitude. It
is obviously a surface phenomenon of the solar atmosphere, primarily,
then followed by consequences involving only the outer surface of the
solar core, but with no observable permanent change in the character
or constitution of the mass of the sun itself. These characteristics
are invariable, and the sequence of phenomena is the same in all the
cases observed.