A Quantitative Test of the No-Hair Theorem with Sgr A* using stars, pulsars, and the Event Horizon Telescope

Understand

The black hole in the center of the Milky Way, Sgr A*, has the largest mass-to-distance ratio among all known black holes in the Universe.

• This property makes Sgr A* the optimal target for testing the gravitational no-hair theorem.
• In the near future, major developments in instrumentation will provide the tools for high-precision studies of its spacetime via observations of relativistic effects in stellar orbits, in the timing of pulsars, and in horizon-scale images of its accretion flow.
• We explore here the prospect of measuring the properties of the black-hole spacetime using all these three types of observations.