Past affiliation(s) within the IAU

• Past President of Commission 33 Structure & Dynamics of the Galactic System (1958-1961)
• Past President of Commission 33 Structure & Dynamics of the Galactic System (1955-1958)
• Past President of Executive Committee (1976-1979)
• Past Chair of Special Nominating Committee (1976-1979)
• Past Organizing Committee Member of Commission 24 Photographic Astrometry (1973-1976)
• Past Organizing Committee Member of Commission 30 Radial Velocities (1967-1970)
• Past Organizing Committee Member of Commission 33 Structure & Dynamics of the Galactic System (1967-1970)
• Past Organizing Committee Member of Commission 33 Structure & Dynamics of the Galactic System (1964-1967)
• Past Organizing Committee Member of Commission 33 Structure & Dynamics of the Galactic System (1961-1964)
• Past Advisor of Executive Committee (1979-1982)
• Past Advisor of Special Nominating Committee (1979-1982)
• Past Member of Division VII Galactic System (until 2010)
• Past Member of Commission 24 Photographic Astrometry
• Past Member of Commission 30 Radial Velocities
• Past Member of Commission 33 Structure & Dynamics of the Galactic System (until 2010)
• Past Member of Commission 41 History of Astronomy (2003-2010)
• Past Member of Special Nominating Committee (1973-1976)