244
11 The Kapteyn Universe
For the sake of completeness I also mention Egbert Adriaan Kreiken (1896–
1964) in the list of PhD students of Kapteyn. He had a special link with
Kapteyn, because his parents had bought the Benno boarding school in Barneveld from Kapteyn’s mother, after Kapteyn’s father had died. So Kreiken and
Kapteyn were born in the same house! Kreiken studied with Kapteyn and
also started his doctoral research with his supervision; Kreiken always considered Kapteyn his real teacher, although he finally defended his thesis with Van
Rhijn in 1923, when Kapteyn had already died. His research concerned the
colors of stars in the Milky Way, based on photographic material obtained by
Ejnar Hertzsprung at Mount Wilson. Kreiken continued to work in astronomy; eventually he founded the Ankara Observatory in Turkey, which is now
named after him [104].
Fig. 11.8 Drawing of Kapteyn from 1920 by Cornelis Easton. This figure comes from an
article on Kapteyn by the latter in Hemel & Dampkring
11 The Kapteyn Universe
For the sake of completeness I also mention Egbert Adriaan Kreiken (1896–
1964) in the list of PhD students of Kapteyn. He had a special link with
Kapteyn, because his parents had bought the Benno boarding school in Barneveld from Kapteyn’s mother, after Kapteyn’s father had died. So Kreiken and
Kapteyn were born in the same house! Kreiken studied with Kapteyn and
also started his doctoral research with his supervision; Kreiken always considered Kapteyn his real teacher, although he finally defended his thesis with Van
Rhijn in 1923, when Kapteyn had already died. His research concerned the
colors of stars in the Milky Way, based on photographic material obtained by
Ejnar Hertzsprung at Mount Wilson. Kreiken continued to work in astronomy; eventually he founded the Ankara Observatory in Turkey, which is now
named after him [104].
Fig. 11.8 Drawing of Kapteyn from 1920 by Cornelis Easton. This figure comes from an
article on Kapteyn by the latter in Hemel & Dampkring