Interferometry on Stars at Mid-Infrared Wavelengths

摘要

The ISI (Infrared Stellar Interferometer), an interferometer operating at mid-infrared wavelengths will be discussed, including both the instrumentation and results of stellar measurements. The ISI operates in the 10 micron wavelength region using three movable telescopes and heterodyne detection with CO_2 laser local oscillators. Phase closure allows rather complete imaging of stars and their dust shells, including measurement of asymmetries. Measurements have been conducted of the emission of material from stars, some ejected at very high velocity, the size and change of size of some stars, stellar ellipticity, and stellar asymmetry. Material blown off from stars is often emitted in periodic shells, and frequently asymmetric.