A bibliometric mapping of the astronomical/astrophysical research area “extrasolar planets”

The purpose of this study was to bibliometrically investigate and describe the research area called “extrasolar planets”. The research questions were: Which authors were mostly cited within the area when the first authors (and their co-authors) were considered? Which authors were found in most co-occurrences? Did particular author collaborations emerge?To which institutions were most authors affiliated and did the size of the institution have an influence on whether an author was cited?What was the geographic distribution of authors and institutions and were there any patterns of collaboration?Did the image of dominating institutions and countries depend on the viewpoint?How applicable was Lotka’s law on the collected data? The data was collected from citation lists in documents from the database Arxiv.org. The documents were extracted by using the search term “extrasolar planets”. By using citation analysis and the method a)”first author counting”, complimented by the method b)”fractional counting” used on a material screened by method a), for accrediting publications to authors and countries, an image of the research area was depicted. Method b) was also used for extracting information about author collaboration and geographic distributions. The most quoted first author, also found in most co-occurrences, was attached to the largest institution, located in USA. Most quoted authors, almost 60%, were attached to USA. However, the results were inconclusive when the viewpoints were changed. Apart from the fact that 57.8% of the quoted documents originated from 9.5% of the first authors, Lotka’s law was not applicable