The sun is the biggest object in our solar system . . . but our solar system is only a small part of the universe. What about other stars? They look like tiny specks of light in the night . . . but are they really tiny?
Arcturus is one of the brightest stars you can see in the sky on a summer night. If you lined up 25 stars the size of the sun, they would be about as wide as Arcturus, which means Arcturus is definitely big.
There are other stars that are even bigger. like the star Betelgeuse! You would have to line up 40 stars the size of Arcturus (or 1,000 stars the size of the sun) to be as wide as Betelgeuse.
Is the sun big? As the only star in our solar system, it seems big, but when you find out how big some other stars are, the sun doesn't seem so big anymore.