Is the sun the biggest?

The sun is not the largest, but it is the largest in the solar system, accounting for 99%. Stars larger than the sun have the largest celestial bodies in countless solar systems. No, it is the largest in the solar system, but there are many other celestial systems.

The sun is definitely not. The universe is so big that it is hard to say which is the biggest. But I can tell you which star is the biggest. That's the biggest red giant. This is the last form of star evolution, and its volume is usually very huge. Compared with the red giant, the sun is nothing in size. But the mass of the red giant is basically the same as that of the sun, so the density of the red giant is very small.

Betelgeuse in Orion and arcturus in Capricorn are both red giants. It will be billions of years before the sun becomes a white dwarf. At that time, humans were either extinct or technologically advanced enough to immigrate to other planets.