The nearest star that is known to have a potentially habitable exoplanet is Proxima Centauri, which is part of the Alpha Centauri star system. Proxima Centauri is a red dwarf star located approximately 4.24 light-years away from Earth, making it the closest known star to our solar system.
In 2016, an exoplanet called Proxima b was discovered orbiting Proxima Centauri within its habitable zone, also known as the "Goldilocks zone." The habitable zone refers to the region around a star where conditions may be suitable for liquid water to exist on the surface of an orbiting planet, which is considered an essential ingredient for Earth-like life.
Proxima b has a minimum mass of about 1.3 times that of Earth and orbits its host star at a distance of approximately 0.05 astronomical units (AU). It completes an orbit around Proxima Centauri in approximately 11.2 Earth days. While the discovery of Proxima b is exciting, many details about its composition, atmosphere, and potential habitability are still unknown.
It's important to note that determining the potential habitability of exoplanets is a complex task, and there are many factors beyond proximity to consider. Other factors include the planet's atmosphere, surface conditions, presence of a magnetic field, and many more. Future observations and advancements in technology will help us refine our understanding of exoplanets and their potential for hosting Earth-like life.