# The Galactic Center

## TL;DR

High-resolution infrared observations of the Galactic Center have confirmed a three million solar mass black hole, providing key evidence for black hole existence and insights into physics near the event horizon.

## Contribution

This paper reviews recent high-resolution infrared measurements that establish the presence of a supermassive black hole at the Galactic Center and discusses implications for astrophysics and black hole physics.

## Key findings

- Confirmation of a three million solar mass black hole
- Detection of young massive stars near the black hole
- Variable infrared and X-ray emissions from Sagittarius A*

## Abstract

In the past decade high resolution measurements in the infrared employing adaptive optics imaging on 10m telescopes have allowed determining the three dimensional orbits stars within ten light hours of the compact radio source at the center of the Milky Way. These observations show the presence of a three million solar mass black hole in Sagittarius A* beyond any reasonable doubt. The Galactic Center thus constitutes the best astrophysical evidence for the existence of black holes which have long been postulated, and is also an ideal `lab' for studying the physics in the vicinity of such an object. Remarkably, young massive stars are present there and probably have formed in the innermost stellar cusp. Variable infrared and X-ray emission from Sagittarius A* are a new probe of the physical processes and space-time curvature just outside the event horizon.