Star Clusters

Abstract

IN 1915–18, Dr. Shapley published a remarkable series of researches on globular clusters which brought these remote objects into the forefront of astronomical interest. His results indicated an extension of the flattened system of the galaxy about ten times greater than had previously been adopted. This was the beginning of a phase in astronomy which its critics might describe as megalomania. The same method has since been applied to the still more distant spiral nebulae, and these have tended to displace the globular clusters in their appeal to our imagination. From the observational point of view, however, there is no comparison between the stage of advancement of the two subjects. As regards the spirals, our systematic knowledge is summed up in a fairly trustworthy calculation of the size and distance of three or four of the nearest of them, a guess at the distances of the remainder, and the astonishing fact that almost without exception they are running away; as regards the star clusters, we have before us Shapley's monograph, closely packed with statistics and individual studies, with a wealth of problems and deductions which interact with and illuminate our knowledge of the stars in our immediate neighbourhood.

Star Clusters.

Harlow Shapley. (Harvard Observatory Monographs, No. 2.) Pp. xi + 276 + 3 plates. (New York: McGraw-Hill Book Co., Inc.; London: McGraw-Hill Publishing Co., Ltd., 1930.) 15s.