STELLAR STRUCTURE.

Kaipara and Waitemata Echo, 1 May 1914, Page 2

STELLAR STRUCTURE.

(By EDGAR LUCIEN LARKEN.)

The siueral universe, the temple of Ihe stars, in the eyes of astronomers is becoming more an<J more impressi\e in its magnificence with each new discovery. The very limits of imagination in the mind of man in its present state of advancement are reached ; and then expanded. Supposing- an almast invisible grain of sand should get into the wheels of a watch and disturb their motions ; then this would be comoarable to the appearance of any minute new moon in the solar machine. The disturbance of other bodies by its attraction would soon be detected by modern microscopic accuracy of observation. And then the new stranger would be in the clut-.h of high mathematics within a day or two. it would be measured and weighed in short order. The solar system having been conquered mid explored, then the inconceivably greater machine, the universe of suns far and away in the distance, was the object of research. The early astronomers had only the telescope, but moderns have two most powerful engines of research, the tele-spectroscope and telecamera. The excessively sensitive and rapid plates in the focal planes of huge telescopes make record of all that the great lenses rescue from the oblivion of space deeps. Uncounted millions of suns make their imprint on the plates, ready to be counted by microscopes : then later photographs are secured, and one plate compared with its mate soon reveals the motion of any flying sun. But a greater is the photographing of the spectra of glowing suns. These spectra, containing Fraunhofer lines, the true alphabet of nature, reveals the chemical elements that compose these distant white and red hot suns. Plates record these lines, and later photographs detect any chemical changes. By studying photographic dry plates that have been exposed all night, centred on any one selected small area in the sky, and measuring the minute distances and angles between the small points, each the image of a giant sun. the distances of these suns have been determined with greater accuracy than by any of the older methods. Even with this new method, surpassing all others in accuracy, it is found impossible to measure the space between us and suns that are farther away than 100 light-years. A light-year is the distance , traversed by light in 100 years, moving with the known specific speed of 186,380 miles per second.