Astronomy Bio...Heber Curtis

Jay Bitterman

Heber Doust Curtis was born in Muskegon, Michigan, on June 27, 1872. He went to High School in Detroit where he exhibited an interest in the classics and languages. He concentrated his efforts primarily in these subjects while a student at the University of Michigan. In 1892 Curtis received his BA and a year later his MA. His first job was teaching Latin at his old high school in Detroit. At the age of 22 he became Professor of Latin at Napa College, California, where he immediately became aware of the availability of a refracting telescope and small observatory.

In 1897 Curtis abruptly changed the direction of his career and became a Professor of Mathematics and Astronomy at the University of the Pacific. In 1898 he worked at the Lick Observatory, California; in 1900 he became Vanderbilt Fellow at the Leander McCormick Observatory at the University of Virginia; and in 1902 he returned to the Lick Observatory to become an assistant. In 1904 he was promoted to Assistant Astronomer. In 1906, under the auspices of the observatory, he took charge of work being done at an observatory in Chile. In 1909 he again returned to Lick as an astronomer until he retired from research work in 1920. He was next appointed to the directorship of the Allegheny Observatory, a post that he held until 1930, when he became director of the observatory at the University of Michigan.

In 1900 he initially studied total solar eclipses in Thomaston, Georgia. In 1901 his studies continued in Solok, Sumatra. The main value of Curtis' early work at the Lick Observatory was his contributions to the program for the measurement of stellar radial velocities, under the direction of William Campbell (1862-1938). He continued work on this program at Mount Hamilton from 1902 until 1906. From 1906 to 1909 he worked on this project in Chile. During the next eleven years Curtis concentrated his efforts on photographing "spiral nebulae" and on research into their nature.

Ever since Charles Messier had included "nebulosities" in his Catalogue of 1771, their precise composition had been the subject of dispute. The two main schools of thought was that they were either giant star clusters far beyond our own galaxy as proposed by Richard Proctor (1837-1888) or that they were simply clouds of debris. The scale of the universe itself was central to both theories. By photographing the spiral nebulae, Curtis began to comprehend the actual vastness of space and leaned toward Proctor's view of "islands in the universe". He also perceived on photographs of spiral nebulae viewed "edge on" that there was a dark line along the rim of each nebula.

This suggested to Curtis a combination of the two theories' that spiral nebulae might indeed be complex galaxies like our own, and that such galaxies produced a cloud of debris which accumulated in the plane of the galaxy. If such a cloud of debris had also gathered outside our own galaxy, this would explain the reported "zone of avoidance" where spiral nebulae never appeared in the Milky Way (i.e. in the plane of our own galaxy). Spiral nebulae in that position, it now was evident, would simply be obscured by dust.

He died in Ann Arbor, Michigan, on January 8, 1942.

Published in the June 2001 issue of the NightTimes