Excerpt:
Apart from the Vikings, who without doubt navigated and kept track of time by means of the stars, the first important Danish astronomer was Peder Nightingale. In 1274 he observed the sunlatitude from Roskilde where he was a canon, and based on these observations he made tables showing the length of day and nights. Later he published a widespread calender in Paris. There is some indication in the sources, that he didn't believe in the relation between astrology and astronomy which was the common belief at that time.
In 1417 were "Speculum Planetarum" published by Johannes Simones de Selandia a book about the movements of the planets, very little is known of Johannes.