Jacobus kapteyn biography

For the Dutch-Ghanaian minister, see Jacobus Capitein.

Jacobus Cornelius Kapteyn (19 January 1851 – 18 June 1922) was a Dutch astronomer.

He carried out extensive studies of the Milky Way. He found that the apparent movement of stars was not randomly distributed but had two preferential directions: the two star streams.

Jacobus kapteyn biography

This discovery was later reinterpreted as evidence for galactic rotation. Kapteyn also suggested that these stellar velocities could be used to find the amount of non-luminous matter in the galaxy.^[1]

Biography

Kapteyn was born in Barneveld to Gerrit J.

and Elisabeth C. (née Koomans) Kapteyn,^[2][3] and went to the University of Utrecht to study mathematics and physics in 1868. In 1875, after having finished his thesis, he worked for three years at the Leiden Observatory, before becoming the first Professor of Astronomy and Theoretical Mechanics at the University of Groningen, where he remained until his retire