Julius
Mac Leod

Ghent University (Chemistry Tree)








Anton
Pannekoek

Amsterdam


Jan
Woltjer

Leiden (Astronomy Tree)








Robert Grant
Aitken

Lick Observatory (Astronomy Tree)


Gerard P.
Kuiper

University of Arizona






Fred
Hoyle

Cambridge


Leon
Mestel

Trinity College, Cambridge


Walter
Baade

Mount Wilson Observatory


Edwin Powell
Hubble

Mount Wilson Observatory (Astronomy Tree)




Allan Rex
Sandage

Mount Wilson-Palomar




Simon David Manton
White

Max-Planck-Institut für Astrophysik

Amina
Helmi

RUG
(Options)

Amina HelmiX