
J. Allen Hynek
Josef Allen Hynek (May 1, 1910 – April 27, 1986) was an American astronomer, professor, and ufologist. He is perhaps best remembered for his UFO research. Hynek acted as scientific advisor to UFO studies undertaken by the U.S. Air Force under three projects: Project Sign (1947–1949), Project Grudge (1949–1951) and Project Blue Book (1952–1969). In later years, he conducted his own independent UFO research, developing the "Close Encounter" classification system. He was among the first people to conduct scientific analysis of reports and especially of trace evidence purportedly left by UFOs. Description above from the Wikipedia article J. Allen Hynek, licensed under CC-BY-SA, full list of contributors on Wikipedia.
Filmography

The Phenomenon
as Self (archive footage)
The Phenomenon
as Self (archive footage)

Out of the Blue
as Self (archive footage)
Out of the Blue
as Self (archive footage)

UFOs: 50 Years of Denial?
as Himself
UFOs: 50 Years of Denial?
as Himself
The UFO Experience
as Himself
The UFO Experience
as Himself

Close Encounters of the Third Kind
as Man Smoking Pipe at Landing Site (uncredited)
Close Encounters of the Third Kind
as Man Smoking Pipe at Landing Site (uncredited)

UFO's Are Here!
as Self
UFO's Are Here!
as Self
We Know What We Saw
We Know What We Saw