Trends in astronomical publication between 1975 and 1996

Trends in astronomical publication have traditionally been studied by examining the few thousand papers published in a few selected journals within a few selected years. With the development of comprehensive bibliographic databases such as ADS and SIMBAD, publication trends can now be studied using tens of thousands of papers published in a number of refereed astronomy journals. The ADS has extensive bibliographic information on almost every paper published in seven major astronomy journals over the past two decades; the SIMBAD database can be used to verify critical bibliographic information such as the number of authors and the length of the papers, Here we present results of a study of astronomical publication trends using 76,000 papers published in A&A, A&AS, AJ, ApJ, ApJS, MNRAS, and PASP between 1975 and 1996, Two trends are particularly interesting: the fraction of single-author papers has decreased by about a factor of three in the last 20 years, while astronomical papers with more than 50 authors have become increasingly common since 1990.