In speaking of Orion, we referred to the marvelous star θ situated in the no less famous Nebula, below the Belt; this star forms a dazzling sextuple system, in the very heart of the nebula (Fig. 20). How different to our Sun, sailing through Space in modest isolation!
Be it noted that all these stars are animated by prodigious motions that impel them in every direction.
Fig. 20.—Sextuple star θ in the Nebula of Orion.
There are no fixed stars. On every side throughout Infinity, the burning suns—enormous globes, blazing centers of light and heat—are flying at giddy speed toward an unknown goal, traversing millions of miles each day, crossing century by century such vast spaces as are inconceivable to the human intellect.
If the stars appear motionless to us, it is because they are so remote, their secular movements being only manifested on the celestial sphere by imperceptible displacements. But in reality these suns are in perpetual commotion in the abysses of the Heavens, which they quicken with an extraordinary animation.
These perpetual and cumulative motions must eventually modify the aspect of the Constellations: but these changes will only take effect very slowly; and for thousands and thousands of years longer the heroes and heroines of mythology will keep their respective places in the Heavens, and reign undisturbed beneath the starry vault.
Examination of these star motions reveals the fact that our Sun is plunging with all his system (the Earth included) toward the Constellation of Hercules. We are changing our position every moment: in an hour we shall be 70,000 kilometers (43,500 miles) farther than we are at present. The Sun and the Earth will never again traverse the space they have just left, and which they have deserted forever.
And here let us pause for an instant to consider the variable stars. Our Sun, which is constant and uniform in its light, does not set the type of all the stars. A great number of them are variable—either periodically, in regular cycles—or irregularly.