Pieter C. van der Kruit

“Jacobus Cornelius Kapteyn (1851-1922) was an astronomer who was a pioneer in the study of the structure of the Milky Way Galaxy. This Jacobus Cornelius Kapteyn (1851-1922) biography that is not technical presents the scientific life of the astronomer to the general reader. The author incorporates the fundamentals of astronomy throughout the narrative of Kapteyn’s life and makes use of contemporary astronomical imagery to demonstrate how astronomical research has progressed from Kapteyn’s time period to the present day. In particular, the investigation into the dispersion of stars throughout space has now reached its zenith, culminating with the spectacular new insights that have come from the astrometric satellite Gaia, which is currently receiving a lot of attention from the general public.

The biography demonstrates how Kapteyn’s ideas had an impact on prominent astronomers all over the world. He is well known for his work as the Kapteyn Universe designer, an alternative to the large system that Harlow Shapley discovered. Kapteyn’s Star is still the second fastest moving star in the sky, and it is now one of the nearest stars that have a planet in the habitable zone. He is known as the discoverer of Kapteyn’s Star.

This fascinating combination of astronomy history and popular astronomy tells the story of an astronomy professor who did not have access to an observatory but established the first astronomical laboratory that specialized in measuring photographic plates in other locations. Kapteyn shifted the focus of astronomy away from simply cataloging stars and toward measuring their distances and velocities in order to investigate their spatial distribution, Kapteyn’s Star Streams, and the equilibrium that exists between their gravity and motions. Jan Hendrik Oort, a famous astronomer from Leiden, was a student of Kapteyn’s and was so inspired by Kapteyn’s lectures that he decided to become an astronomer. This is part of Kapteyn’s legacy. In addition to the first application of Galactic structure and dynamics, his legacy also includes Jan Hendrik Oort.”