Much is still a mystery; but what has been ascertained during the period that the rhythm of its light-waves beat upon our shores is of great interest and importance as bearing directly on the life-history of each individual star in the heavens, and of our own sun and planet among them.
The first and simplest question that arises for settlement is the date when the new star blazed forth in our terrestrial sky. The curious reader will notice the reservation: in our terrestrial sky. When the star actually burst forth into resplendent light is another matter, as we shall discover later on. It was certainly before Dr. Anderson was born, and probably before another Scotsman—Ferguson by name—combined, like many another sage, counting and watching sheep with counting and watching stars.
With regard to the date of the appearance in our sky of the new star, Nova Persei, as it is called in astronomical literature, when Dr. Anderson discovered it at twenty minutes to three o’clock on the morning of 22d February, it was bright enough to be straightway evident to a trained astronomer. In these later days of strenuous scientific activities every portion of the sky is constantly being examined and charted, and no sooner was the discovery of Nova Persei announced than a searching of records began, in order to ascertain if, at any time, the star had ever been seen before.
Fig. 19.—Chart Showing Position of Nova Persei
It so chanced that on the evenings of 18th and 19th February two photographs of the very spot where three days later the new star appeared were taken at Harvard Observatory. On neither of these photographs is there the slightest evidence of the star’s existence. It was, therefore, on these dates non-existent so far as our earth was concerned. On the evening of 20th February a well-known English observer, Mr. Stanley Williams, had also taken a photograph of the same portion of the sky; and again there was no trace of the star. Mr. Williams’s photograph was taken twenty-eight hours before Dr. Anderson saw it. Still more strange is the fact that on the evening of 21st February three observers on the Continent testify that they had the constellation Perseus under observation from seven o’clock to eleven, and had the new star then been visible they could not have failed to see it. The star, therefore, blazed out some time between eleven o’clock and three on the night of its discovery.
Now, what does this mean? It means this: that by some cause a star, quite dark before, or so faint that it could not be seen even by means of a powerful telescope, in a few hours, or perhaps in a few minutes, blazed forth as a star of conspicuous brightness. In this brief space of time a dark and probably chill globe became a seething mass of fire, a million times hotter than it was before. Fierce, fervent heat lit up the orb with a glow that reached from rim to rim of the stellar universe. We have here a catastrophe that goes beyond our wildest conceptions: the conflagration of a world, the ruin of a star. What guarantee have we for an assumption of this kind? What of certitude is there in our vision of such a Day of Doom for any part of our universe? Let us consider the salient facts regarding the recent changes in the appearance and structure of this star. We shall relate only those facts that are beyond controversy, as far as our present knowledge goes.
Nova Persei did not reach its maximum brightness till the evening of 25th February, when it was probably the most conspicuous object in the midnight sky. It was then at least six times brighter than at the time of its discovery. After this date it began to wane slowly. At intervals there were spurts of brightness lasting for two or three days, as if the fires had not exhausted themselves. On the whole, however, the light of the star waned, and by the end of the year its enfeebled light was just bright enough to be evident to the naked eye; twelve months after its appearance it could only be seen with the aid of a telescope.
Now, one of the most powerful instruments of research in the new astronomy is the spectroscope. It takes hold of the rays of light that come to us from a star, and makes these rays reveal the condition of things in the world they come from. One of the spectroscopes turned on the new star in Perseus was Professor Copeland’s magnificent instrument at Blackford Hill Observatory, Edinburgh. Professor Copeland described the new star as “a feebly developed” sun. As the star, however, increased in brightness the spectroscope chronicled the fact that great physical changes were taking place in its composition and structure. The star soon ceased to be a feebly developed sun, for development had gone on apace with the increase of light. Round the solid or semi-molten mass there was rapidly aggregating an ocean of fiery gases, probably thrown up from the nucleus.
Put simply, Nova Persei, for long ages a cold, dark, solid globe, was in the brief space of a few days transformed from circumference to core into a luminous, heated gaseous sphere. By what chance or circumstance this vast change came about may be inquired into later on. We only note here that this was the story spelled out by those skilled in deciphering the observations recorded by the spectroscope. In July, 1901, Professor Pickering of Harvard Observatory announced that the star had become a nebula; that, indeed, its once solid globe had practically dissolved into thinnest air. Not only had its elements become molten with fervent heat, but they had become transformed into shimmering wisps of matter more diaphanous than a gossamer web.