What is the structure of the Milky Way galaxy?

The Milky Way galaxy is a spiral galaxy with a central bulge and spiral arms.

The Milky Way galaxy is approximately 100,000 light-years in diameter and contains billions of stars, gas, and dust. The central bulge of the galaxy is a dense region of stars, gas, and dust that is shaped like a football. Surrounding the bulge are four spiral arms that extend outwards from the center. These arms are made up of stars, gas, and dust that are organized in a spiral pattern. The arms contain many young, hot stars and regions of active star formation.

The Milky Way galaxy also contains a halo, which is a spherical region of gas and dark matter that surrounds the galaxy. The halo is much larger than the visible portion of the galaxy and is thought to contain a large amount of dark matter. Dark matter is a mysterious substance that does not emit, absorb, or reflect light, but is thought to make up a significant portion of the mass of the universe.

The structure of the Milky Way galaxy is constantly changing due to the motion of its stars and the gravitational influence of nearby galaxies. Scientists continue to study the Milky Way galaxy in order to better understand its structure and evolution.