Jasper County Democrat, Volume 6, Number 3, Rensselaer, Jasper County, 25 April 1903 — SELECTIONS [ARTICLE+ILLUSTRATION]

SELECTIONS

NORTH BTAR 13 THREE SUNS. Uo EJr« ai Uw Telaaeope Oaa to* Them, bat the Camara Pmu It. The nows from Lick observatory that the North Star, 255,000,000,000 miles away from us, has been found to be not one star, but three, swinging around In great orbits Tike the moon, earth and sun. Is another remarkable result of the application of photo spectroscopy to the telescopic study of the heavens. Always fascinating, the search for doable and multiple stars bas become of tbe highest interest since the spectroscope bas made It possible to discover multiple stars which tbe greatest telescopes do not reveal to the eye. The three components of Folaris cannot be seen with the most powerful telescope In the world. But the Lick star spectroscope, attached to the great 36 inch refractor, makes it plain that there are suns revolving about a sun where the eye distinguishes but one twinkling light. Ten years ago at the Harvard university observatory the first photo spectroscopic multiple star was discovered unexpectedly. The star Mizar, the middle star of the handle of the Big . Dipper, has been called a “naked eye” double because It has a visible companion, Alcor, close to It. But Rlccioll in 1650 discovered with the telescope that Mizar had a telescopic double. Mizar seems to have been tbe first double star discovered with a telescope. The apparent distance between Mizar and Alcor is nearly 40 times the distance that separates the components of Mizar. The telescope shows, too, that there are other stars between Mizar and Alcor.

Two centuries after the telescope revealed two stars in Mizar the spectroscope showed that the brighter of the components was itself made up of two stars. In photographs taken at the Harvard observatory in 1889 the K line in the spectrum of Mizar appeared double. In other plates the line was single; in others it was hazy. A close scrutiny of all the plates showed that the line was double at intervals of 52 days. This proved to astronomers that the brighter component of Mizar was really two stars. A spectroscope takes cognizance of tbe motion of a star to or from tbe earth. When one star begins to approach and the other to recede from us, the lines In the spectrum of the approaching star will be displaced toward the violet end, while those of the receding star will be displaced toward the red end. The lines will at first appear hazy, but when the approach and recession of the stars reach a maximum the lines will appear double. The calculated distance between the components of Mizar Is about 143,000,000 miles, , and the brilliancy of the star is estimated to be over a hundred times greater than that of our sun. A number of other photo spectroscopic multiple stars have been discovered recently. With the Lick telescope and spectroscope 14 have been found. This method of discovery came about from the use of the spectra to determine the velocity with which stars approached or receded from the earth. The North Star, it was found a short while ago, is now shooting earthward at a velocity of 16 miles a second. Two of the suns of the North Star triplet revolvte about each other every four Mays, and these two swing about tbe third.—New York Sun.