"Joint" Stellar light-spot

This chart shows one of the first "joint" light-spots from a star as seen at this VLTI focus and resulting from the superposition of light collected with the 8.2-m VLT ANTU and MELIPAL telescopes. Despite the long optical paths (about 200 m), the quality is excellent (FWHM = 0.45 arcsec). Note that this is not (yet) an image of the stellar surface.