OCR Text |
Show Count the Star. Did you ever try to count all the stars you could sec? Or, thinking I his a hopeless task, did it ever oe- k cur to you that 5,000 would be a generous estimate of their number? This is true The stars of the skv, visible from any one place, may be counted In a few hours under ordinary or-dinary circumstances. If the night is clear. They do not exceed 2,000 or 3,000, the exact number depending upon atmospheric condition and the keenness of the individual eye. Yet, however, many are seen, there is always the vague impression impres-sion of more just beyond the limit of visibility In fact, much more than half of what we call starlight comes from stars that are separately separate-ly too small to be seen, but whose number Is so gTeat as to more than make up for their individual faint- ne3s. The Milky Way is just such a cloud of faint stars, and through Jr the telescope breaks up into shin- ' ing points, each an independent tar. These faint stars, which are found in every part of the sky. as well as in the Milky Way, are usually called telescopic, in recognition of the fact that they can be seen only in the telescope, while the other brighter ones are known as lucid stars. Nearly nineteen centuries ago St Paul noted that "one star differeth from another star in glory," and no more apt words can be found to mark the difference of brightness which the stars present. Even prior to St. Paul's day the ancient Greek astronomers had divided the stars in respect of brightness into six groups, which the modern astronomers as-tronomers still use. calliDg each group a magnitude. Thus a few of the brightest stars are said to be of the first magnitude, the great mass of faint ones which are just visible to the unaided eye are said to be of the sixth magnitude magni-tude and Intermediate degree of brilliancy arc represented by the intermediate in-termediate magnirudes, second, third, fourth and fifth. The telescopic tele-scopic stars show among themselves them-selves an even greater range of brightness than do the lucid ones, and the system of magnitudes has A. been extended to include them, the V fainlest star visible in the greatest m, telescope of the present lime being of the twentieth or twenty-first magnitude mag-nitude The word magnitude has no reference refer-ence to the size of the stars, but only to theii brightness. Some stars do not remain always of the same magnitude but change their bright- jj ness from time to time, and this not on account of cloud or mist in the atmosphere, but from something in " the star itself. These are called variable stars and to their number we must also add certain extraordinary extraordi-nary stars that flash up unexpectedly unexpected-ly where nolbing has been seen be fore, abide for a time and then dti V away These arc called new or temporary stars. |