One of you wrote:
Are there any stars outside our own galaxy that we can see with just the eye?
The answer is no – unless you count seeing the combined light of many billions of stars. From the Northern Hemisphere, the only galaxy outside our Milky Way that’s easily visible to the eye is the great galaxy in the constellation Andromeda, also known as M31. More about the Andromeda galaxy at the bottom of this post.
From the Southern Hemisphere, it’s possible to see two dwarf galaxies, the Large and Small Magellanic Clouds.
So what are we seeing when we look up? The image at the top of this post shows a hazy band in the sky. This is the edgewise view into our own Milky Way galaxy. Our galaxy is about 100,000 light-years in a diameter, but it’s relatively flat, only about 10,000 light-years thick. So – if we’re looking in a dark sky – when we look toward the galactic disk, we see the starry band of the Milky Way.
And when we look up or down – away from the flat disk of the galaxy – we’re also seeing Milky Way stars. All of the stars we see with the eye alone belong to our Milky Way galaxy.