The citation characteristics of astronomical research literature

The citation characteristics of papers in the Monthly Notices of the Royal Astronomical Society (especially for the years 1963-1965) have been examined as a means of studying the usage of astronomical literature in the UK. The decrease of usage with age has been investigated and the decay half-life determined. Particular attention has been paid to the immediacy effect, and to its possible variation in different sub-fields of astronomy. The citations have also been separated according to journal of origin. As a result of this study, a quantitative estimate has been made of the titles and backruns that are required to satisfy a given percentage of the demand for astronomical research literature in this country.