By May 1826, Rümker returned to the observatory, and seven months later he was appointed as the first New South Wales Government Astronomer, though this officially did not happen until a few years later, much to Rümker's disgust, due to delays from his employers in Britain.
V začetku marca 1826 je zapustil Observatorij Paramatta in nadaljeval z delom na svojem domu v ulici Hunter Street v Paramatti.