Journal: Transactions of IAA RAS vol. 40
Keywords: Variable star, VLBI, Astrometry
A relation between pulsation periods and magnitudes (PL-relation) of the Galactic long period variable (LPVs) is studied based on VLBI observations. Calibra tion of the PL-relation applied to the Galactic LPVs is our scientific aim. From 2004, we have been conducting astrometric VLBI observations towards dozens of Mira and semiregular variables to measure their parallaxes. Current result of our ongoing study is presented. As a future plan, we started a study of mid-infrared PL-relations applied to OH/IR stars with period longer than ∼1000 days. We mention a contribution to the study of Galactic kinematics from our research of OH/IR stars.