Aastrup (Åstrup in the post-1948 Danish Orthography) is the name of five villages in Denmark. The name means "Village by a stream" in English. As is the case with many of the names of small Danish villages and towns, Aastrup is also a surname (though not very common). Having Aastrup (or Åstrup) as a surname implies having ancestry from one of the villages.
Chapi