WILL THE METEORIC THEORY ACCOUNT FOR THE PHENOMENA OF VARIABLE AND
TEMPORARY STARS?
Having shown that meteor-asteroids are diffused in vast quantities
throughout the universe; that according to eminent physicists the
solar heat is produced by the precipitation of such matter on the
sun's surface; and that Leverrier has found it necessary to introduce
the disturbing effect of meteoric rings in order fully to account
for the motion of Mercury's perihelion; we now propose extending the
meteoric theory to a number of phenomena that have hitherto received no
satisfactory explanation.
VARIABLE AND TEMPORARY STARS.
No theory as to the origin of the sun's light and heat would seem to
be admissible unless applicable also to the sidereal systems. Will the
meteoric theory explain the phenomena of variable and temporary stars?
"It has been remarked respecting variable stars, that in passing
through their successive phases, they are subject to sensible
irregularities, which have not hitherto been reduced to fixed laws. In
general they do not always attain the same maximum brightness, their
fluctuations being in some cases very considerable. Thus, according
to Argelander, the variable star in _Corona Borealis_, which Pigott
discovered in 1795, exhibits on some occasions such feeble changes of
brightness, that it is almost impossible to distinguish the maxima
from the minima by the naked eye; but after it has completed several
of its cycles in this manner, its fluctuations all at once become
so considerable, that in some instances it totally disappears. It
has been found, moreover, that the light of variable stars does not
increase and diminish symmetrically on each side of the maximum, nor
are the successive intervals between the maxima exactly equal to each
other."--_Grant's History of Physical Astronomy_, p. 541.
Of the numerous hypotheses hitherto proposed to account for these
phenomena we believe none can be found to include and harmonize all
the facts of observation. The theories of Herschel and Maupertius fail
to explain the irregularity in some of the periods; while those of
Newton and Dunn afford no explanation of the periodicity itself.[27]
But let us suppose that among the fixed stars some have atmospheres
of great extent, as was probably the case with the sun at a remote
epoch in its history. Let us also suppose the existence of nebulous
rings, like those of our own system, moving in orbits so elliptical
that in their perihelia they pass through the atmospheric envelopes
of the central stars. Such meteoric rings of varying density, like
those revolving about the sun, would evidently produce the phenomena
of variable stars. The resisting medium through which they pass in
perihelion must gradually contract their orbits, or, in other words,
diminish the intervals between consecutive maxima. Such a shortening of
the period is now well established in the case of _Algol_. Again, if a
ring be influenced by perturbation the period will be variable, like
that of _Mira Ceti_. A change, moreover, in the perihelion distance
will account for the occasional increase or diminution of the apparent
magnitude at the different maxima of the same star. But how are we
to account for the variations of brightness observed in a number of
stars where no order or periodicity in the variation has as yet been
discovered? It is easy to perceive that either a single nebulous ring
with more than one _hiatus_, or several rings about the same star, may
produce phenomena of the character described. Finally, if the matter of
an elliptic ring should accumulate in a single mass, so as to occupy a
comparatively small arc, its passage through perihelion might produce
the phenomenon of a so-called temporary star.
Recent researches relating to nebulæ seem in some measure confirmatory
of the view here presented. These observations have shown (1) a change
of position in some of these objects, rendering it probable that in
certain cases they are not more distant than fixed stars visible to
the naked eye; and (2) a variation in the brilliancy of many small
stars situated in the great nebula of Orion, and also the existence
of numerous masses of nebulous matter in the form of tufts apparently
attached to stars,--facts regarded as indicative of a physical
connection between the stars and nebulæ.[28]