Description
Near-infrared observations of individual stellar orbits have revealed that the Galactic Center hosts a compact mass of around 4.3 million solar masses, honored with the Nobel prize in physics in 2020. By the advent of near-infread interferometry, the resolution and astrometric precision have been increased recently by almost an order of magnitude, turning the stellar system around Sgr A into a laboratory for testing general relativity aorund a large mass. Further, stellar orbits probe the Newtonian mass content in the Galactic Center, and provide stringent constraints on how much dark objects can reside around Sgr A, and constitutes thus a test case for the dynamical modelling used to predict extreme-mass ratio inspiral rates for gravitational wave observations.
