Presentation #343.08 in the session “Milky Way & Galactic Center”.
Gaia DR2 data provide exquisite data on parallax and proper motion of 6,158,038 stars in the Milky Way. These data make it possible to determine the Oort constants in the solar vicinity with unprecedented accuracy. Oort constants parameterize the local stellar motion in radial, longitudinal, and latitude directions. An accurate determination of this set of constants helps us derive the Milky Way rotation curve in the Sun’s immediate vicinity. I divide the sample of Main Sequence stars from Gaia DR2 data into several stellar populations based on their color in order to calculate and compare the Oort constants, A, B, C, and K for each population. I used an MCMC method to determine the uncertainties in the model parameters. A model simulation using test particles is used to examine the limits of the radial and latitudinal range in the Galactocentric coordinates and determine the best 3D regions near the Sun for calculating the Oort constants.