Collaboration: The Photoelectric Photometer


The photoelectric photometer was a great invention that improved the the field of astronomy by leaps and bounds. It started when Joel Stebbins’s wife (May) decided she wanted him home earlier, so she suggested Stebbins make use of electricity. As Stebbins searched for a better method recording star magnitudes, he met and became friends with F.C Brown. Brown was a physicist, who, at a demonstration, used a lamp to illuminate a selenium cell. When the lamp was on, a bell would ring. Turn it off, and the bell would stop.  Brown and Stebbins continued to work together to make an improved selenium cell.


After Brown left to pursue a fellowship at Princeton, Stebbins met Jakob Kunz, a colleague also working at Illinois. Kunz was developing his own photoelectric cell, and the collaboration of the two would result in Kunz’s photoelectric cells being put inside Stebbins’s photometer. From 1913 until his death, Kunz would provide Stebbins with ever new and improved photoelectric cells. According to Stebbins, these cells were far better than any other procurable at the time. Kunz’s cells provided greater sensitivity and faster operation to the selenium ones Stebbins was using.

This collaboration resulted in the measurement of many previously unrecorded stars, as well as several increases in photoelectric technology. 

Joel Stebbins with his invention: the Photoelectric Photometer, circa 1925


Department portrait of Jakob Kunz, signed by him, University of Illinois,  date unknown. 



Click Below to find out more about who was involved:

Joel Stebbins

Jakob Kunz

F.C. Brown

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