Early Professional Years

Abstract

During Christmas vacation 1885 father was reading an article written by David Gill¹, Her Majesty’s astronomer at the Cape of Good Hope, entitled ‘To Lead’ in an astronomical journal about a big project that Gill was hoping to undertake. The project entailed making a catalog of all the stars of the Southern Hemisphere up to the tenth magnitude using photographic techniques. There was a tremendous amount of work that still had not been done. For the northern hemisphere the Bonner Durchmusterung, completed in 1859 under the leadership of Friedrich Argelander² of the Bonner Observatory, already existed. The latter was a catalog of 324 000 stars up to magnitude 9.5 each of which had been recorded visually between the years 1852 and its completion in 1859. Although the positions were provided with reasonable accuracy, the Bonner catalog was of the greatest importance to astronomers. It was virtually the only source for research for ‘the construction of the heavens’,³ which entailed studies of the density⁴ and luminosity⁵ distribution of the stars, as well as the basis of a great number of newer research problems. More than any other, this catalog contributed to an understanding of the movement of the stars. As a result of the Bonner catalog, Argelander brought to light many of the mistakes of other stellar catalogs. Above all, astronomers found this work a faithful and reasonably complete representation of the Northern Hemisphere as understood in 1860.