Prof. Bjorn Ragnvald Pettersen: When astronomy came to Norway - astronomy at UiO during its first 100 years

We review the development of astronomy at the University of Oslo from its introduction as an applied science in 1814. Christopher Hansteen established observing programmes to monitor local time and to determine the coordinates of the capital of young Norway. The latter would serve national surveying and mapping. Hansteen raised funds and acquired modern instrumentation from abroad for a permanent astronomical observatory, constructed 1830-1833. In addition to serving geodesy for the next century, this research centre evolved into new disciplines of astronomy and expanded its instrument collection accordingly. We select some milestones from this history.