Space
What Is the Milky Way? Structure, Spiral Arms, and the Galactic Center
The Milky Way is a barred spiral galaxy with roughly 200 to 400 billion stars. Its disk, central bar, bulge, stellar halo, and dark matter halo are mapped from the inside by Gaia and radio surveys. At the center sits Sagittarius A*, a black hole of about 4.3 million solar masses, imaged by the Event Horizon Telescope in 2022. The Sun orbits about 26,000 to 27,000 light-years out, completing a lap in roughly 200 to 230 million years.