Rotation of the Galaxy; Marriage

Abstract

Rotation of the Galaxy; marriage Oort started his work in Leiden with the problem of absolute declinations and together with Willem de Sitter proposed to build two special observatories at moderate latitudes and one at the equator. With staff member Sanders he reduced data taken by the latter near the equator to show the feasibility. This all led to the first Kenya Expedition which started in 1931. He analysed his data on high-velocity stars, which resulted in a thesis defended in Groningen in 1926. Oort met his future wife and married her in 1927. A study by Bertil Lindblad sparked the idea of differential Galactic rotation, for which he determined the observational consequences and which he subsequently showed existed in available data.