Evidence of a supermassive black hole at the center of the Milky Way comes from a. direct observations of stars that orbit it. b. visible light from material that is falling in. c. strong radio emission from the black hole itself. d. streams of cosmic rays from the center of the galaxy.

The center of our galaxy, the Milky Way, is a bustling and intriguing place. Known as the Galactic Center, it is located about 26,000 light-years away from Earth in the direction of the constellation Sagittarius. One of the most fascinating discoveries about the Milky Way center is the presence of a supermassive black hole. This massive object sits right at the heart of our galaxy and has a mass over 4 million times that of our Sun.
Scientists have gathered a lot of evidence to support this idea, mostly through indirect observations, as black holes themselves do not emit light.
Understanding the core of our galaxy offers insights into the nature of galaxies and the role supermassive black holes play in their evolution.

One of the most convincing pieces of evidence for the supermassive black hole at the Milky Way's center comes from studying stellar orbits. Stars near the Galactic Center move in paths that are incredibly fast. These rapid orbits suggest they are influenced by a massive object that cannot be seen directly. Through the use of advanced telescopes and techniques, astronomers have been able to track these stars over time.
By observing the elliptical orbits and the high velocities of these stars, scientists can infer the presence of a massive yet invisible object—believed to be the supermassive black hole known as Sagittarius A*.
This method of using the motion of stars to detect hidden massive objects is a powerful tool in astronomy.

Astronomical observations are key to understanding distant cosmic phenomena, including the supermassive black hole at the Milky Way's center. These observations can be made in various wavelengths of light, from radio waves to X-rays. For instance, while visible light is often blocked by interstellar dust in such dense regions, radio waves can penetrate through, allowing astronomers to gather critical data.
One significant observation involves detecting radio emissions from the region around Sagittarius A*. These emissions come from hot gas and energetic particles swirling around the black hole, although they are not as direct or conclusive as observing stellar orbits.
In addition to radio waves, other wavelengths like infrared have been pivotal in observing the energetic and dynamic environment around the Galactic Center, helping to build a more comprehensive picture of the supermassive black hole's existence.