Milky Way
Our home galaxy: a barred spiral roughly 100,000 light-years across, containing an estimated 100–400 billion stars.
- Diameter
- ~100,000 light-years
- Type
- Barred spiral (SBbc)
Source: NASA Milky Way overview
Galaxies
Island universes of billions of stars.
Andromeda Galaxy (M31)
The nearest large galaxy, about 2.5 million light-years away, on a slow collision course with the Milky Way in ~4–5 billion years.
- Distance
- ~2.5 million ly
- Diameter
- ~220,000 light-years
Source: NASA M31 overview