In astronomical imaging, the observational technique for achieving the highest spatial resolution, capable of discerning the finest-scale structure on the sky, is to combine the light from multiple telescopes separated by substantial distances. As is well known, the spatial resolution achieved by such an interferometer is roughly as good as that of a single giant telescope of diameter equal to the individual telescope separations. Technical challenges with interferometry are large, as the light must be brought together in instrumentation that is extremely stable mechanically, on the scale of optical wavelengths. A scientific target of continuing promise for optical interferometry is the study of stars, and stellar surfaces in particular, the subject of this project.
This project will conduct a set of upgrades to the Navy Precision Optical Interferometer (NPOI) that will ultimately enable an increase in the number of resolution elements on the surface of a star by a factor of 10-20 or more over existing instruments, and will furthermore allow the production of stellar images with time resolution of a few days. This project will implement the interferometric techniques of baseline bootstrapping, coherent integration, and image reconstruction, significantly enhancing the capabilities of NPOI for imaging stellar surfaces. The science benefits will be major, and may include major impacts in other areas of optical interferometry. No other technique could deliver the kind of science that will be enabled by these developments.
These research advances, in uncovering new knowledge about stars, will no doubt improve our understanding of our own sun and the solar activity cycle. Solar activity has vitally important impacts on many aspect of life on earth, possibly including the weather.
Funding for this project is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.
