Final answer:
When an object is compressed within its Schwarzschild radius, it becomes a black hole, with Sgr A* having a Schwarzschild radius of approximately 11,848,000 kilometers.
Step-by-step explanation:
According to general relativity, if any object is compressed within its Schwarzschild radius, it becomes a black hole—a region in space where the escape velocity exceeds the speed of light, and therefore, not even light can escape. The Schwarzschild radius (Rs) is calculated using the formula Rs = 2GM/c², where G is the gravitational constant, M is the mass of the body, and c is the speed of light. For the center of our Galaxy, the supermassive black hole named Sgr A*, with a reported mass of around 4 million solar masses, the calculation of its Schwarzschild radius would be:
Rs = 2(6.67384 × 10⁻¹¹)(4 × 10⁶)(1.9885 × 10³⁰) / (3.00 × 10⁸)² = 11,848,000 km.
This radius represents the boundary of the event horizon for Sgr A*, beyond which no information or matter can return.