Milky Way

The Milky Way, home to the Solar System, is one of the densest, most massive spiral galaxies known, and the dominant member of the Local Group by mass. While its stellar disc is physically smaller than Andromeda's, our home galaxy has about half again the mass of its already giant neighbor, at least 1.9 trillion Solar Masses as a lower estimate, a third of which is visible in some manner. This suggests a total stellar population around 600 billion, but could be as high as a few trillion.