The Milky Way Galaxy consists of a thin disk containing dust, gas, and young and old stars; a spherical halo containing populations of very old stars, including RR Lyrae variable stars and globular star clusters; a… The gaseous distribution in the Galaxy’s disk has two main spiral arms that emerge from the ends of the central bar, along with several fainter arms and short spurs; the Sun is located in one of those spurs.

The total mass of the Galaxy is about 2 × 10 12 M Sun. The Sun is located roughly halfway out of the Milky Way, about 26,000 light-years from the center

Milky Way Galaxy — the band of light encircling the sky, which is due to the many stars and diffuse nebulae lying near the plane of the Milky Way Galaxy. spiral arm — a spiral-shaped region, characterized by relatively dense interstellar material and young stars, that is observed in the disks of spiral galaxies. halo — the outermost extent of our Galaxy (or another galaxy), containing a sparse distribution of stars and globular clusters in a more or less spherical distribution. Sun — located roughly halfway out of the Milky Way, about 26,000 light-years from the center.