National Astronomical Observatory, Mitaka, Tokyo 181, Japan
MIRA is a series of ground based optical/infrared interferometer arrays, promoted by GOJIRA group (Group Of Japanese optical and Infra-Red interferometer Astronomy) for astrometry and astrophysics in the first decade of the next century starting from MIRA-I, the present experimental two-element interferometer at Mitaka with 4m N-S baseline, to the final MIRA-III, which will be constructed at one of the world best site for astronomical observations like Mauna Kea, Hawaii, in 2002 throught 2005. The main structure of MIRA-III is an eight-element Y-shaped optical/infrared (up to K-band) interferometer with the maximum baseline length longer than 200m. The size of the mirror of each siderostat is planned to be 1.2m in diameter.
LIGHT is an scanning astrometric satellite for stellar and galactic astronomy planned to be launched between 2007 and 2010. Two sets of Fizeau-type 40cm-pupil interferometers with 1m baseline are the basic structure of the satellite optics. The multi-color CCD arrays are thought to be arranged in the focal plane of the interferometer optimized for detecting the precise locations of fringe patterns. LIGHT is expected to observe the parallaxes and proper motions of nearly a hundred million stars up to 18th visual (15th K-band) magnitude, as well as precise photometric characteristics of the observed stars, with the precision better than 0.1 milli-arcsecond (about 50 micro-arcsecond in V-band and 90 micro-arcsecond in K-band) in parallaxes and 0.1 milli-arcsecond per year in proper motions. The almost all of the giant and supergiant stars belonging to the disk and halo components of our Galaxy within 10 to 15kpc from the sun will be observed by LIGHT to study the most fundamental structure and evolution of the Galaxy.