A SUN IN FLAMES.

New Zealand Times, Volume XXXII, Issue 4998, 31 March 1877, Page 2 (Supplement)

A SUN IN FLAMES.

(From the Spectator .) Strange news has recently reached us from the star-depths. Wo say news, but in reality the event of which we have just heard must have occurred many years, possibly many hundreds of years ago. A star made its appearance on 24th November last in the constellation of the Swan, not far from the star Eho of that constellation. The new-comer was then of the third magnitude. If a star just beyond the limits of ordinary vision had increased in brightness until it shone as a star of the third magnitude, that would show that one among the suns which people space had suddenly blazed out with twenty or thirty times its former lustre. But in reality something far more horrible than this would seem to have happened. Astronomers have surveyed the heavens far too diligently for a star of even the eighth or ninth magnitude to have escaped their notice where the new star appeared. Argelander’s charts of the heavens alone include 324,000 stars, or about a hundred times as many as can be seen with the naked eye in the same half of the star-sphere. But the new star is not one among the 324,000. Most probably it was, only a few weeks ago, a star of a magnitude below the twelfth, in which case it was shining last November with seven or ei"ht hundred times its former lustre. -It had suddenly, from some unexplained cause, been excited to an intense degree of heat, a change which must have been accompanied by most disastrous effects if that sun, like ours, was the centre of a scheme of circling worlds. "When the catastrophe happened we do not know. We have just said that the new star was shining last November with greatly increased lustre, but we mean simply that it was so shining to our eyes. The light which brought the news to us was probably at least a hundred years on the journey. For we know that from the nearest star light takes more than three years in reaching us, from Sirius some fifteen or twenty years, and probably light takes many hundreds of years in reaching us from most of the twelfth-magnitude stars. 11 may be asked, however, how astronomers ; C an be assured either that the new star was not really a new orb, only at the time and for a time—since the star has greatly faded in lustre assuming the functions of a sun, or that, if really an old sun, it can be called a sun in flames. Of old, the stars that blazed out suddenly in the heavens were regarded as new stars, and as they presently died out, came to be called temporary stars. Such was the star the appearance of which led Hipparchus to construct his famous catalogue, such Tycho Brahe’s in 1572—-the reappearance of which in Cassiopeia may be looked for within .the next few years—such Kepler s star in the Serpent-bearer. All these blazed out until they exceeded in brightness every fixed star in the heavens, and even Jupiter at his brightest, being surpassed by Venus alone. They were all three visible, in fact, in full daylight. They soon lost this splendor, however, and none of them remained visible more than sixteen months. But when a bright star appeared in the Northern Crown in May, 1866, which in old times would have been regarded as a new star, astronomers found the benefit of their careful survey of the heavens. The star was only new as a bright star. It had been observed twice in Argelander’s survey of the heavens as a ninth-magnitude. And again, after it had faded from ordinary vision, astronomers continued to observe it with their telescopes. It did not disappear from their view, but remains visible, with a telescope of rather small power, to this day. This is the star T not Tan, as Koscoe mistakenly calls it—of the Northern Cross. It was the same body which first showed astronomers what has happened when a new star makes its appearance. Examined with a spectroscope, it gave the rainbow-tinted streak, crossed by dark line*, which implies that a star is a' sun like our own, a glowing mass of solid or liquid matter, shining through relatively cool, though absolutely very hot, vapors. But it gave, besides, a spectrum, showing that such a sun had suddenly been enwrapped in flames of glowing gas. For on the rainbow-tinted streak, as on a dark background, there were seen the lines of hydrogen, not dark as usual, but intensely bright. The well-known interpretation of this appearance was that the hydrogen surrounding that star was not as usual, cooler than the glowing body of the star, but hotter, and very much hotter.

The star which has jnst appeared has given similar, but more decisive, evidence. Besides the bright lines of hydrogen, the spectrum of the new star shows the double orangeyellow bright line of sodium, or, perhaps (for the point cannot be determined), the line of that unknown element which produces the most marked orange-yellow line in the spectrum of the sun's colored prominences, the triple bright line of magnesium, and two other bright lines, one of which seems to be identical with a line given by the solar corona during total eclipse. It is noteworthy, and to say the truth, somewhat portentous, that the elements to whose intense heat the new star owes its increase of brightness are precisely those whose lines form the most characteristic features of matter surrounding our sun. M. Conm, who made the observation, declines to form any opinion on the meaning of this fact, assigning as his, “exquisite reason” that “ whatever attractions hypotheses may have, it is necessary not to forget that they are unscientific, and that far from serving science, they greatly tend to trammel her ” (which is about as just as though one should say that whatever attractions the use of raw material in manufacture may possess, we must not forget that manufactures are not the raw material, and that far from tending to encourage the producer of the raw material, they greatly tend to trammel him.) Fortunately, Newton, Galileo, and some others, whose names are not wholly unknown to science, have been willing to think as well as to observe, and their “unscientific” example has been followed in our own time. Accordingly, after Mr. Huggins had determined the spectrum of T. Corona;, he reasoned about its meaning, and so effectually as to suggest one of the most fertile methods of observation yet invented the spectroscopic method of seeing the sun’s colored flames. Certainly M. Cornu, who has acquired well-deserved repute by observations which never would have existed had not reasoning been applied to observed facts, should not object to reasoning as unscientific. It is, indeed, impossible for any thoughtful student of science to avoid reflection upon the significance of what has been observed in the case of the new star in Cygnus. Here we find the same elements which exist in our sun, but ordinarily in such a condition that they partially absorb his lustre, have in the new star been excited to so intense a degree of heat that their light is very much stronger than that of the globe they envelope. The fact is rendered still more significant by the circumstance that in the case of our own sun those same elements glow with a heat more intense than that of the sun’s own surface, though—fortunately, perhaps, for us—the increase of heat is only local, and very limited indeed in range. Tacchini noticed that during the great heats of a recent summer the magnesium in a portion of the solar sierra was heated in this abnormal way, and though there may have been no real association between tho heated magnesium and the hot weather experienced over nearly the whole of our northern hemisphere, yet on the other hand the association may have been very close indeed. The Astronomer-Koyal for England has lately noticed, as tho Astronomer-Iloyal for Scotland had observed earlier, that our earth receives in some years more heat from without than in others. We now see that suns which have unmistakeably blazed out with many times their usual degree of lustre have had the constituents of their exterior atmosphere superheated, in the same way as the corresponding elements in the sun's atmosphere are occasionally (though but locally) superheated. The question naturally arises whether the cause which produces the effects observed in our. own sun is not in all probability of the same nature as that which produces great solar outbursts ; and, if so, whether it is altogether certain that this cause may not one day operate more extensively and effectively on out own sun than it has yet done, and product) such an outburst as seems foreshadowed in tho description of the day “when the heavens shall pass away with a great noise,

and the elements shall melt with fervent heat; the earth also, and the works that are therein, being burned up." Fortunately, great outbursts occur so seldom among the iinilhons of stars within telescopic range as to suggest that the chance of any given sun—our own, for example—suffering in this wa Jf is but small. Moreover, Sir J. Herschel (who was not afraid of tramelling science by that unscientific process called thinking), has noted that the danger seems limited to those suns which belong to a particular region of the Milky Way— a region to which our; own sun does not belong.