July—Libra and Scorpio
With a telescope of medium size, one will find an exquisite little green companion-star close to Antares. The little companion is so close to Antares that it is difficult to find it in the glare of light from its more brilliant neighbor. Antares is one of the giant stars of the universe. In fact it is, so far as we know, the greatest of all the giants. Its diameter is more than five hundred times that of our own sun and nearly twice that of the giant star Betelgeuze in Orion. If placed at the center of the solar system its surface would lie far beyond the orbit of Mars.
Both Ophiuchus and Scorpio are crossed by the Milky Way, that broad belt of numberless faint stars that encircles the heavens. Some of the most wonderful and beautiful regions of the Milky Way are to be found in these two constellations.
At various times in the past, there have suddenly flashed forth brilliant stars in the Milky Way which are known as "temporary stars," or "novæ." These outbursts signify that some celestial catastrophe has taken place, the nature or cause of which is not clearly understood. Some of the most brilliant of these outbursts have occurred in these two constellations. The life of a nova is very short, a matter of a few months, and it rapidly sinks into oblivion, so nothing is to be seen of some of the most brilliant of all these stars that have appeared in this region in the past. A few are still faintly visible in large telescopes.
[IX]
AUGUST
It was one of the twelve labors of Hercules, the hero of Grecian mythology, to vanquish the dragon that guarded the golden apples in the garden of the Hesperides. Among the constellations for July we found the large group of stars that represents the hero himself, and this month we find just to the north of Hercules the head of Draco, The Dragon. The foot of the hero rests upon the dragon's head, which is outlined by a group of four fairly bright stars forming a quadrilateral or four-sided figure. The brightest star in this group passes in its daily circuit of the pole almost through the zenith of London. That is, as it crosses the meridian of London, it is almost exactly overhead. From the head of Draco, the creature's body can be traced in a long line of stars curving first eastward, then northward, toward the pole-star to a point above Hercules, where it bends sharply westward. The body of the monster lies chiefly between its head and the bowl of the Little Dipper. The tail extends in a long line of faint stars midway between the two Dippers, or the constellations of Ursa Major and Ursa Minor, the tip of the tail lying on the line connecting the Pointers of the Big Dipper with the pole-star Polaris.