Disk Mass Potential

The purpose of this project is to make direct measurements of distances to and proper motions of disk stars. We will combine these with the results from the Fundamental Galactic Parameters study (determining our position and velocity in the Galaxy), and will be able to measure:

1. The rotation curve of the Milky Way, which is the orbital speed of stars versus distance from the Galactic Center. This will tell us the underlying mass distribution in the inner Galaxy.

2. The nature of large-scale asymmetries such as open spiral arms or a "warp" in the Galactic disk (see examples for other galaxies below). This will provide insight into disk dynamics and the interaction of disk with other Galactic components.

   The spiral arms of galaxy M74

   Warped spiral galaxy ESO510-13

3. Kinematic properties of different age populations, which will allow us to study the formation and evolution of the disk.