JASMINE: near-infrared space astrometry mission

JASMINE is a satellite mission to perform infrared astrometric observations in the direction of the Galactic nuclear region. JASMINE was selected by ISAS/JAXA (Institute of Space and Astronautical Science/the Japan Aerospace Exploration Agency) for the JAXA Competitive Middle-Class Science Missions No.3. This mission is unique in that the same astronomical object can be observed frequently, and observations will be performed in the near-infrared band, in which the effect of absorption by dust is weak. JASMINE uses an infrared camera under development in Japan to observe in the Hw band of wavelengths from 1.0 microns to 1.6 microns. JASMINE will determine parallaxes (proper motions) accurate to between 25 μas (25μas/y)and 125 μas (125μas/y), depending mainly on the star magnitude. This mission will help to achieve revolutionary breakthroughs in astronomy and astrophysics, including the formation history of the Galactic nuclear structures (Galactic Center Archeology) and the supermassive black hole at the Galactic Center etc. In terms of understanding our Galaxy’s structure, and its formation and evolution, the Galactic nuclear region is particularly important region because stars of various ages have different spatial distributions and motions according to their ages in this region although this region covers only a small part of the sky. It’s like having different strata in geology. JASMINE will also be useful for exploring dark matter, black holes, X-ray binary star systems, and stellar clusters, in the inner region along the Galactic plane. The brief overview and recent progress of the JASMINE mission will be explained.