Man's physical universe

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MANY INSTRUMENTS SUPPLEMENT TELESCOPE 75

Stars Have Been Grouped as Constellations.

The constellations of the stars have no scientific significance except

as an aid in naming and locating stars. The constellations are merely

groups of stars that ancient man imagined to fall into definite groups

whose formations traced the lines of various objects, in which animals

predominated. Thus two bears, several dogs, a lion, a bull, a ram, a

horse, a dragon, a couple of serpents, a crab, an eagle, a whale, a swan,

and a crow have been named. The Big and Little Dippers are the

most familiar figures.

Fig. 10. The changing constellations. The arrows represent the directions in

which the stars are moving and the distance which they will travel in the next

50,000 years. Note how the Taurus stream is converging. The effect is one of

perspectives. (Drawing by Donald Howard Menzel in Stars and Planets, published

by The University Society. Reproduced by the courtesy of Popular

Mechanics.)

Today the brighter stars are usually referred to by name. Thus

Vega, Arcturus (made famous by the Century of Progress Fair at

Chicago), Betelgeuse, Polaris, Sirius, etc., are well-known stars. Common

names would soon run out and would be of no value in locating

stars for scientific purposes, so they are named either by Greek letters

according to their magnitude in generally accepted constellations, or

they are simply numbered according to their position in a given section

of the sky.

The accompanying diagram shows how the relative positions of the

stars in the various constellations change with time. The constellations

do not represent true groups of stars, such as the globular star clusters,

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