How far away is the center?

If we knew the distance to the Globular Clusters, we could find the distance to the center of their distribution = distance to the point they’re orbiting around
Get distance:
- Trigonometric Parallax? TOO FAR
- HR-Diagram? Generally too far (no suitable nearby stars similar to the luminous GC ones)
SOLUTION: Use stars of known luminosity to find the distance to Globular Clusters! (Cepheid Variable Stars)

If we knew the distance to the Globular Clusters, we could find the distance to the center of their distribution = distance to the point they’re orbiting around