FIND VELOCITY OF STAR IS OVER 650 MILES PER SECOND

Nearly two and a half million miles per hour, or over 650 miles per second, is the extraordinary speed at which the star RZ Cephei is moving through space, according to a discovery made public by the Harvard College Observatory last night. This star has been found by University astronomers to have a greater velocity than any other star whose speed has yet been determined.

RZ Cephei, a variable star of the so-called cluster type, has long been known to astronomers, but its velocity was never measured until recently. It is far too faint to be seen with the naked eye, being of the tenth magnitude. It is in the constellation Cepheus, and is 3800 light years distant from the earth, which means that the light from it which astronomers now see through their telescopes started on its journey to the earth in the time of the shepherd kings of Egypt, nearly nineteen hundred years before Christ. That distance is only a small fraction of the distance from the earth to some of the more distant star-clusters, but the outstanding fact about RZ Cephei is that its velocity is the greatest yet known for a star.

Measured by Complicated Process

The speed of the star was measured at the University Observatory by a complicated process of observations and computations, including among other things the comparison of photographs recently taken here with others taken 31 years ago, when the Observatory was just beginning its task of preserving a photographic history of the entire sky. Since that time a "sky patrol" has been kept without interruption at Cambridge, supplemented by photographs taken at the station at Arequipa, Peru, and the history of the stars down to the eleventh magnitude has been written by the stars themselves on over a quarter of a million photographic plates weighing in all 140 tons.

Most of the discoveries made by the University astronomers are not made by looking through a telescope at night, as is popularly supposed, but by doing what was done in the case of this discovery of the speed of RZ Cephei, that is, by studying and measuring by day, in the laboratory, photographs taken at night, and by computing the significance of the changes in the brilliance or position or spectra of the stars as recorded on these plates.

The discovery of the immense speed of RZ Cephei is said to be important to astronomers as suggesting that this type of variable star escapes from the globular clusters, a hypothesis suggested also by other recent observations.