|What is it?
The Navy Prototype Optical Interferometer, instead of using a single telescope,
combines the light from an array of up to six mirrors spaced tens of meters apart by precisely
directing the beams of light from a star to a point. Extraordinary stellar image detail can be
derived from the resulting data called an interference pattern.
Why Use a Stellar Interferometer?
An optical interferometer works with light that can be best gathered and directed with mirrors
and lenses, generally from the visible light through near infrared light. However, an astronomical
interferometer is a useful technique for recording extraordinarily high detailed (resolution) images
at any wavelength of light (the electromagnetic spectrum) including radio wavelengths. In fact, radio
interferometers became practical instruments several decades before optical interferometers
(VLA). The technical advantages of longer wavelengths
and how radio signals are recorded enabled the early advancement of radio interferometers.
The following discussion pertains to optical interferometry and the Navy Prototype Optical Interferometer specifically.
Tour the NPOI