Joel Stebbins

Joel Stebbins (July 30, 1878 – March 16, 1966) was an American astronomer who pioneered photoelectric photometry in astronomy.

He used the new technique to investigate eclipsing binaries, the reddening of starlight by interstellar dust, colors of galaxies, and variable stars.

He received his Bachelor of Science (BS) degree in 1899, and remained for a year as a graduate student before leaving for the University of Wisconsin–Madison, where he studied astronomy at the Washburn Observatory under George C.

He earned his Doctor of Philosophy (PhD) degree there under the supervision of William Wallace Campbell, writing a thesis on the spectra of Omicron Ceti.

Beginning in 1907, Stebbins began the first measurements using the selenium cell photometer first on the moon and then later, as the sensitivity of the instrument was improved, on variable stars.

By 1913, Henry Norris Russell had developed the theory of eclipsing binaries, and Stebbins realized that there were many undiscovered ones.

Kunz's photoelectric cells were many times more sensitive than what was available commercially and therefore able to detect faint star light.

[6] The University of Illinois Observatory has been designated a National Historic Landmark based on the significance of Stebbins' and Kunz's work.

Stebbins conducted systematic photometric studies of the O-type and B-type main-sequence stars and globular clusters.

[9] Having dealt with the bright Cepheids, Stebbins and Kron used photometric techniques to study the Sun, which is orders of magnitude brighter than any other object in the sky.