The Astronomical Journal (often abbreviated AJ in scientific papers and references) is a peer-reviewed monthly scientific journal owned by the American Astronomical Society and currently published by IOP Publishing. It is one of the premier journals for astronomy in the world. Until 2008, the journal was published by the University of Chicago Press on behalf of the American Astronomical Society. The reasons for the change were given by the society as the desire of the University of Chicago Press to revise its financial arrangement and their plans to change from the particular software that had been developed in-house. The other two publications of the society, the Astrophysical Journal and its supplement series, followed in January 2009.