Strong evidence for the existence of a dense cloud of island universes, where conditions are three times as congested as those of average space, has been found by Harlow Shapley, director of the College Observatory. The cloud lies well beyond the range of all but very powerful telescopes and is located in the region of the sky that includes the southern constellations, Horologium, Roticulum, and Dorado.
Dr. Shapley's announcement followed upon the completion of the largest existing catalogue of external galaxies, issued today, and tabulated during the past five years by Miss Sylvia Mussells of the astronomical staff.
The catalogue contains descriptions of 7,889 galaxies in the Horologium area, almost all of them hitherto unknown, and nearly all of them fainter than the fifteenth magnitude. It was compiled from a series of long exposure photographs taken with the Bruce telescope at the University's southern observatory in Bloomfontein, South Africa.
The "metagalactic cloud" of galaxies found by Dr. Shapley is about twice as dense in population as space in general. Within the cloud are found several concentrations, in which the population is about three times that of average space.
The area surveyed in the catalogue, while containing 7,889 galaxies, each of which fills as much as 5,000,000,000,000 cubic light years, covers somewhat less than one percent of the total sky.
The catalogue of the galaxies in the Horologium area is part of the general survey of external galaxies in progress at the University. Objects are recorded according to position, brightness, diameter, form, and structure.
Previous to this catalogue, the largest catalogue of galaxies ever made was the famous "New General Catalogue," published in Ireland fifty years ago, and containing records of about 7,000 objects.
This earlier catalogue included almost exclusively objects brighter than the fifteenth magnitude, and covered the whole sky. The present catalogue deals, for the most part, with objects fainter than the fifteenth magnitude, and confines itself to a very small area.