Here's what you need to know:
* Individual Star Sizes: The stars in a binary system can range from tiny red dwarfs, only a little bigger than Jupiter, to massive blue supergiants, hundreds of times larger than our Sun.
* Total System Size: The size of the entire binary system depends on the distance between the two stars. Some binaries are close together, while others are separated by vast distances.
* Example: A famous binary system is Alpha Centauri, which includes Proxima Centauri, the closest star to our Sun. Proxima Centauri is a red dwarf, while the other two stars, Alpha Centauri A and B, are similar to our Sun in size. The system is relatively close, with Proxima Centauri orbiting the other two stars at a distance of about 13,000 astronomical units (AU).
Therefore, to know how big a binary star is, you need to consider the sizes of both individual stars and the distance between them.
