Page:The Music of the Spheres.djvu/112

 and was named in memory of Charles I by Halley, the English astronomer, on the suggestion of the Court Physician, Sir Charles Scarborough.This star is an attractive double as viewed in a small telescope with the delicate colorings of "flushed white and lilac." On the head of Asterion lies the famous whirlpool nebula, although this may only be seen in a large telescope. This nebula has its great arms of nebulous material flung widely into space and looks as if it were whirling rapidly about, but the motion, if any, is too slow for us really to see. With a few exceptions most of the spiral nebulæ are so very distant that they may only be seen through a very large telescope, but next to the stars, they are the most abundant objects in all the sky and are of great interest to astronomers.

Arcturus, the beautiful first magnitude star which glows so conspicuously in the constellation of Boötes, is, however, the main source of interest in these star groups. The star is popular for its appearance alone, for it is large and richly golden, and always easily located, but it is also of interest in a scientific way, for it has been found to be an extremely huge and glorious sun. Our sun placed at the same distance—145 millions of millions of miles—would shine as a faint and almost invisible star, yet Arcturus is so much larger than our sun that it drifts across our sky like a bowl of light.

Arcturus is not only one of the largest but it is also one of the swiftest moving stars in the heavens. It moves so swiftly that it covers 100 miles in every second. This speed has caused it to be labeled a "runaway star." Although this star shoots through space at such an incredible rate of speed it has taken it 800 years to describe a space (as seen by our eyes) equal to the apparent diameter of the moon. This may give the reader some slight realization of the vast distance which separates us from Arcturus.