Abstract

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an eight-meter baseline Michelson interferometer designed to fly on a high-altitude balloon. The long baseline, in combination with a double-Fourier Michelson interferometer, provides high angular resolution (~0.5″) in the 30–90μm band with spectral resolution of up to R ≡ λ/Δλ ~ 200. The capabilities provided by the double-Fourier instrument therefore allow BETTII to provide spatially-resolved spectroscopy, which will in turn enable exploration of important astrophysical regimes that are hidden from the view of current instrumentation.

© 2013 Optical Society of America