COUNTING THE STARS.

Auckland Star, Volume LXVIII, Issue 25, 30 January 1937, Page 10 (Supplement)

COUNTING THE STARS.

Those who have to make it their business to watch the stars through the night have counted thousands. A famous astronomer with exceptionally keen sight counted 4000 from an observatory in Germany. Professor Pickering counted 5710 from Jamaica; and a third astronomer counted 7756 from Cordoba in South America. It has h»«n estimated that if the atmosphere cou/d bo wholly withdrawn fully 25,000 starts would become apparent to moderately good eyes. A lens of over five inches raises the number to 7.000.000. Astronomers are not satisfied to count the stars. They early began to classify them according to their brightness, which they rather misleadingly spoke of as "magnitude." There are *10 stars of the first magnitude in the northern hemisphere. and 10 in the southern, though they are not equally bright. . Sirius. the brightest, is 14 times as bright as Regulus. and Vega more than twice as bright as Aldebaran. Vega Capella and Areturus are about equally bright. Stars of the second magnitude are the seven stars of the Plough, and some of the most vivid penis in the constellations of Perseus and Cassiopeia's Chair. The rough rule is that stars of anv one magnitude are rather less than "three times as bright as the one next in order. Stars of the sixth magnitude are the faintest that ordinarily can be seen. Another rough rule about them is that there is a fairly constant increase in the stars with each successive magnitude. so that the number of one magnitude is between three and four times greater than that of the next brighter magnitude. At present great telescopes reveal -tars of the eighteenth magnitude. If the rule of increase held good we ought to arrive at a total of 1.400.000,000 of stars. Actually, the law fails after the thirteenth magnitude, and 1.000.000.000 stars is the highest number that can be brought by any means before our eyes.