High Angular Resolution Community Science at the CHARA Array

The Center for High Angular Resolution Astronomy (CHARA) Array is the nation’s premier facility for long baseline optical interferometry. With the number and size of its telescopes, the length of its baselines, and the range of wavelengths covered by its beam combiners, the CHARA Array is a uniquely powerful facility for milliarcsecond imaging. With adaptive optics and four new beam combiners, the Array is reaching deeper than ever. Since 2004 CHARA results have appeared in some 245 papers in the refereed literature. This includes observations obtained during the high-demand open access program supported by NSF for some years, and operated in collaboration with NSF’s National Optical-Infrared Research Laboratory. This award extends that program for another three years, and includes a new snapshot imaging mode. The team also plans to offer user support, community workshops, and an accessible data archive. CHARA will foster collaborations with amateur astronomers through the American Association of Variable Star Observers. CHARA trains graduate students to build and use precision technology. The CHARA Array achieves sub-milliarcsecond resolution at visible and near-infrared wavelengths, and can be used to resolve the radii of stars all along the main sequence and at different stages as stars evolve off the main sequence. The Array reveals the impact of limb- and gravity-darkening, the spatial distribution and size of star-spots and activity in convection zones, and provides physical properties of exoplanet host stars. The CHARA Array resolves binary stars, maps orbits, and probes interacting systems. Extragalactic observations probe the structure of Active Galactic Nuclei cores to show how supermassive black holes impact accretion and trigger outflows. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.