Practical study of optical stellar interferometry

Abstract

We present a technique to observe stellar inteferograms, as well as the detailed analysis of those created by three bright stars: Betelgeuse, Rigel, and Sirius. It is shown that the atmospheric turbulence is responsible for the reduction of the long-exposure fringe visibility of the obtained interference patterns. By using different baselines in our interferometer, we are able to distinguish the decay of the visibility with the baseline, observe how different parameters such as the diameter or the distribution of the holes in our interferometer affect the pattern, and measure the atmospheric turbulence. This experiment can be performed by postgraduate students to gain practical experience in optical interferometry in astronomy.