While he pursued a number of aspects of astronomy, Greenstein devoted much time to his lifelong study of White Dwarfs.

“Jesse did more than anyone to establish the characteristics of these in the 1930s. He will most probably be remembered for that,” said Jonathan E. Grindlay, chair of Harvard’s astronomy department.

Grindlay, who credits Greenstein with opening new avenues in the field of astronomy, said that even after Greenstein left Harvard, he remained involved in Harvard’s astronomy department.

He served as a member of a visiting committee that came to lecture at Harvard during the 1960s and 1970s.

“He was very interested in what students were doing, very interactive with the department,” Grindlay said. “He was just a real inspiration.”

Kirshner, who teaches Science A-35, “Matter in the Universe,” first met Greenstein as an undergraduate astronomy concentrator during one of Greenstein’s visits to Harvard. Kirshner met up with Greenstein again during his own graduate studies at Caltech.

Kirshner said he remembers being impressed by Greenstein’s “tremendous presence.”

He was, according to Kirshner, a man who “treated you like you were the next best thing. He had a manner of treating you, a totally powerless pawn, as an equal, even though you weren’t.”

Even after his retirement in 1979, Greenstein continued to observe the stars, making his last trip to the Palomar Observatory in 1983, at the age of 85.