ABOUT THE NEW STAR

Dominion, Volume 11, Issue 225, 11 June 1918, Page 7

ABOUT THE NEW STAR

SUNS IN COLLISION

AN IMMENSE CELESTIAL

EXPLOSION

The appearance of the new star in 'Aquilae is an incident that will attract tho very keenest interest in astronomical circles all.over the world. New stars are Tare, andificy are usually so remote from tho earth that they are scarcely visiblo, if visiblo at all, without the aid of powerful telescopes. But the star that is now reported has become at once ono of tho brightest in the heavens, and its study may help towards the solution.of Bomc of the most vexed problems in the •whole fiold of nstronomy. It is tho brightest nova tjhat has appeared since IBM. 'Inevitably it will recall to tho minds of Many Now Zealand peolo the writings and the lectures of Professor A. W. Bickerton, whoso theory of stellar impact soems to bo in process of acceptance, after years of scepticism and neglect, by the leading astronomers of the day. Tho astronomer sees in the visitor something uvorte than an additional twinkle in the sky. Ho knows that three days «ko the portion of space now occupiod by the star was ■apparently empty. Suddenly, -within a period of a few hours, thero has appeared a star that is many hundreds, probably many thousands, of . times as large and as brilliant as our own sun. A stupendous celestial bonfire has been lit; it may be expected to increase in brightness for a few days, and then, like other now stars that have beon recorded, it will become dimmer. It may disappear altogether within a few weeks. What can have happened to produce such a result? The only apparently feasible expplanation ever offored is that two dead suns, rushing towards one another at a Telocity of probably several hundred miles a second, have collided, a.nd that •what we are seeing now is the stupendous flash produced by the blow. The actual collision is likely to have occurred centuries ago, but the rays of. light, travel, ling through space at the rate of 186,000 miles a second, have only just brougnt tho news to our earth. The distances involved are unthinkable; but oven the layman can have some comprehension of the forces that havo produced this result, i- :

Professor Biokcrton was not the first student of astronomy to suggest that now stars were tho results of 6teflar collisions. The 6tars that can bo seen in the night Bky are suns, most of them immensely larger and hotter than our Ban, and they shine by their own light. But in addi•tioh thei'O .are countless "dead" suns. These cannot be seen at all, though their presence is made known in various ways. The occurrence of occasional collisions) is '& prouabiTity that would occur to many men, sinco it is obvious that if two suns approached ono another in the illimitable areas of space they would be affected by 1 'force of gravitation. They would tend to "fall", towards ono another. Tho collision theory, while it explained the sudden blaze; Of. light in tho sky, did not seem to explain tho, rapid disappearance. It was left to Professor Bickerton to give form and coheronoo to.theory by his discovery of the "third body." The- "third body" is the product of "partial impact," a term that Professor Bickerton mado vory familiar to audiences in many parts'of New Zealand.and to readers'of scientific publications in all parts of the world. When the two stars began to bo attracted towards one another they would each have motion of their own. They would be travelling through space in ordered progress as units of tho sidereal system. Their mutual, attraction' would deflect them. They would swing towards ono'another'in curves, the process .extending perhaps ■ over hundreds of years,' and when the collision finally canio it nearly always would be a graze, not a head-ou collision. At tho velocities they had acquired, the hardest substances would be almost infinitely soft. .'Tiio graze, slight or severe, would not stay their headlong rush.. Portions of tiie stars would be sheared off, the stare themselves would pass on, and between fthem would be loft-the "third body," in a state of explosive incandescence, as a -result of the conversion of stupendous kinetic energy-into ; heat. ' '' "Before Biins collide," wrote Professor Bickerton, "they have • been falling towards each other and getting up. speed for hundreds of years. In their final velocity every particle has an energy many scores of million times that of. an express train. • l This tremendous tearing, speed is stopped Buddenly in the colliding ' parts, and . is .converted into a motion of molecules—that is, into heat. So the .new body is welded, fused, and made into,gas'ten thousand times as hot as our'., hottest furnace, whilo a pressure of many millions of atmospheres tends to Mow. the glowing body into its separate atoms! Thus by a tearing blow, in about an hour a new star is born. The explosive force expands it, and the giant bonfire swells out its diameter at a. speed of millions of miles an hour. This was the story of Tycho Brahe's Btar. It is also tho story of "Nova Persei,"'the new-star of the new century, that sudden apparition that lit up the dark'nights of our Northern Hemisphere a few years ago. "Thus by the expansion of its newly-lit orb the new star of the constellation Perseus grew to be the brightest star in the firmament. It was an immense distance away—probably it actually exploded some hundreds of year's ago, and its cy-

plicr message travelling at llio rate of some 186,000 miles a second, took all that tinio to tell us its story. In one day Nature lit and turned up that wondrous lamp until its blazing light had many hundreds of thousands of times the brilliancy of the central orb of our little solar system.

"After that comes tho fading of that marvellous light. Tho bright star throws off shells of gas, the swift light atoms going first; then the slower ones; element after olement following according to the weight of its atoms. As these gases are dissipated into space the light of the bright star diihinishes, by degrees, until in a few weeks it is nearly gone. The heaviest atoms have expanded into an almost non-luminous meteoric swam; the lightest gases are wandering as isolated atoms in space; and tho atoms of intermediate weight are forming the ensphering shells of a planetary nebula." The hydrogen atoms, being the lightest, would form the outer shell of incandescent gas, and already the Now Zealand Government Astronomer has reported that when he was examining the spectrum of tho latest star "a slight indication of one of tho bright hydrogen lines waR glimpsed." Stellar collisions would be of almost infinite variety, ranging from tho merest gram to a direct Wow, involving the merging of the two bodies in whirling incandescence. Bat it is not intended hero to attempt to follow the "partial impact" theory through all its deductions aJid extensions. The purpose of this bnief survey is merely to show that the appearance in tho sky of a new star if.a really interesting, and, to (he thoughtful nianj an nwe-inspiring event. What wo are witnessing may be an enirnious stellar catastrophe; it may be a phase of the birth of worlds and systems.

A Press Association tole?ram from Wanganui states: "Mr. J. T. Ward, Director of theWanganui Observatory, reports that word has been received of the discovery of a new 6far in the constellation Aquarius. Observations at Wanganui show that its brilliancy is greater than that of a star of tho first magnitude. Mr. Word says some great stellar catastrophe must have taken place. It may bo that.a dark 6tar has crashed into a cloud of cosmic matter, and thus generated this enormous outburst of light and. heat. It is so far away that the catastrophe possibly happened hundreds of years ago, its light waves, though travelling 6ix hundred sfnd eeventy million miles per hour, taking all this time to reach us. Changes are taking placo in' its light as viewed by the spectroscope." NEW STAR Wnln ENGLAND ' (Rec. June 11, 0.25 a.m.) London, June 9. A large aew star of magnitude 0.9 has suddenly appeared in the constollation of Aquilla. It was discovered in several places on Saturday night, and is easily visible to the naked eye.—Renter,