Flowers of the Sky

by Richard A. Proctor

Even these changes, however, though justly regarded as among the chief wonders and mysteries of the star-depths, seem in turn to sink into nothingness by comparison with the sudden appearance of a new star, as interpreted by modern scientific observations. Of old, when a new star appeared, it was thought for awhile to be a fresh creation; a new sun set in the centre of a new system of worlds,—a thought which was not then so startling as in our own times it would be reckoned. When the new star was seen slowly to die out until at last it became invisible, men were content to regard it as a sign set in the heavens for a special purpose. Nor did they find much difficulty in associating such a phenomenon with some event of importance occurring during its continuance, or soon after the new star had died out. Such were the explanations offered respecting the exceedingly bright star which made its appearance in the constellation Cassiopeia in the year 1572. The place in which it appeared is shown in [fig. 7]. It must have sprung into its full glory in a very short time, for Tycho Brahé, the celebrated astronomer, tells us that, returning on November 1, 1572, from his laboratory to his dwelling-house, he saw the new star, which he was certain had not been visible an hour before, shining more brightly than any before seen. It surpassed all the stars in the heavens in brilliancy, and even Jupiter when that planet is at its brightest. Only Venus at her brightest was superior to the new star. For three weeks it shone with full lustre, after which it began slowly to decline. Being situated in a part of the heavens always above the horizon (for European observatories), the star's entire history could be followed. It remained for sixteen months steadfast in its position like the other stars. As it decreased in size it varied in colour. "At first," says an old writer; "its light was white and extremely bright; it then became yellowish; afterwards of a ruddy colour like Mars; and finished with a pale, livid white, resembling the colour of Saturn."

Fig. 7.—Cassiopeia; showing where a new star appeared in the year 1572.

In passing it may be remarked that there are reasons for expecting the return of Tycho Brahé's star in the course of a few years. For other new stars have been recorded as seen in the same part of the heavens in the years 945 and 1264, and though the interval from 945 to 1264 (or 319 years) exceeds by 11 years the interval from 1264 to 1572 (or 308 years), yet the difference is but small by comparison with either entire interval; and we may not unreasonably believe that the three new stars seen in Cassiopeia have been only three apparitions of one and the same star, which shines out, with superior lustre, for a few months, once in a period averaging about 313 years. It seems to me not at all unlikely that, some time during the next twenty years, astronomers will have an opportunity of examining, with the telescope and spectroscope, a star which last appeared before either instrument had been invented.

Already facts are known respecting the so-called new stars which will not permit us to accept the explanations of old so readily offered and admitted, simply because so little was certainly known.

In the year 1866 a star appeared suddenly in the constellation of the Northern Crown, where no star had before been visible to the naked eye. It was a little below the arc of stars forming the celestial coronet.[7]

It shone as a second magnitude star when first seen, but very rapidly diminished in lustre. It increased our knowledge in two important respects.

First, on examining Argelander's charts of the northern heavens, the new star was found to have been observed and charted as a tenth magnitude star, that is, four magnitudes below the lowest limit of naked eye vision. It was not, then, a new sun, though it might still truly be called a new star, in this sense, that it was a new member of the set of stars which adorn our skies as seen by ordinary vision.

In the second place, the star was subject to the searching scrutiny of spectroscopic analysis, with results of a most interesting character.