Education
Starting circa 1924, he studied Jupiter"s Galilean satellites, minor planets, comets, and the proper motions of faint stars, in particular members of the Hyades cluster.
Starting circa 1924, he studied Jupiter"s Galilean satellites, minor planets, comets, and the proper motions of faint stars, in particular members of the Hyades cluster.
After following secondary school in Utrecht, he was appointed "computer" at the Leiden observatory in 1919. He computed orbital characteristics for many of the minor planets discovered by Hendrik van Gent. She, together with January Oort, published their work on the Hyades cluster in 1975, 9 years after his death, in the journal Astronomy and Astrophysics.