John Krom
Rees

Columbia


Harold
Jacoby

Columbia






George E.
Hale

Yerkes Observatory






Julius
Mac Leod

Ghent University (Chemistry Tree)


Leonard Salomon
Ornstein

Utrecht (Physics Tree)


Paul
Ehrenfest

Leiden (Physics Tree)


Marcel G.J.
Minnaert

Utrecht (Physics Tree)




Anton
Pannekoek

Amsterdam








Robert Grant
Aitken

Lick Observatory


Gerard P.
Kuiper

University of Arizona








Bart J.
Bok

University of Arizona


Thomas Arnold
Matthews

University of Maryland


Richard Brent
Tully

University of Hawai'i at Manoa

Marcus Adrianus Wilhelmus
Verheijen

RUG
(Options)

Federico
Lelli

European Southern Observatory (ESO)

Marcus VerheijenX