> While software and algorithms have become increasingly important in astronomy, the majority of authors who publish computational astronomy research do not sha

> While software and algorithms have become increasingly important in astronomy, the majority of authors who publish computational astronomy research do not share the source code they develop, making it difficult to replicate and reuse the work. This is troubling. There's no field involving computation in which withholding source code is routinely accepted. The four-color map theorem proof (Appel & Haken, 1976) would never have been accepted without source code. Modern mathematics, to the degree to which it relies on computer results, also relies on the publication of source. Another example is the recent revelation involving an error in an Excel spreadsheet and its effect on an economic analysis -- the correction wouldn't have been possible without publication of the spreadsheet alongside the conclusions drawn from it. Also, replication is a cornerstone of serious science. Without replication, astrophysics becomes psychology, where replication is rare. I hope this paper has the effect of correcting this systematic flaw in astrophysics publication.