Astronomical Interferometry
From 1920 and into 1921 Michelson and Francis G. Pease became the first individuals to measure the diameter of a star other than the Sun. They used an astronomical interferometer at the Mount Wilson Observatory to measure the diameter of the super-giant star Betelgeuse. A periscope arrangement was used to obtain a densified pupil in the interferometer, a method later investigated in detail by Antoine Émile Henry Labeyrie for use in "Hypertelescopes". The measurement of stellar diameters and the separations of binary stars took up an increasing amount of Michelson's life after this.
A century later, the specific interferometer instrumentation design produced by Albert Michelson has become the principle means to conduct astronomical interferometry. The "Michelson Interferometer" design is found on modern operational observatories such as VLTI, CHARA – and the U.S. Navy's NPOI.
Read more about this topic: Albert Abraham Michelson