Not counting the sun, which star is the closest to Earth?

Proxima Centauri is indeed the closest star to Earth, aside from the sun. It is part of the Alpha Centauri star system, which includes Alpha Centauri A and Alpha Centauri B. Proxima Centauri is located about 4.24 light-years away from our planet. This proximity makes it the nearest known star to the solar system, and its classification as a red dwarf star allows for significant study on the possibility of habitable planets in such nearby systems.

Understanding the distances between stars helps clarify why Proxima Centauri holds the distinction of being the closest. Other stars, such as Sirius and Betelgeuse, are much farther away, with Sirius being about 8.6 light-years from Earth and Betelgeuse at approximately 642.5 light-years. This context emphasizes Proxima Centauri's unique position in relation to our solar system.