3.2 Finding the Monster

summary

There’s a thin layer of sodium atoms 90 km up in the atmosphere.
Using lasers to create an artificial star in this layer of sodium atoms, Professor Ghez can calculate how to adjust the deformable mirror.
The star is S0-2 orbits closest to the supermassive black hole at the center of the Milky Way. Studying S0-2 helps understand the curvature of spacetime.
Using S0-2, Ghez was able to show that the 4E6 solar masses located at Sagittarius A* are in fact a supermassive black hole.