What is the Closest Star to Earth?

Alpha Centauri C, also called Proxima


Alpha of Centauri is a special Star – not only because it is closest to our solar system, but it is also one of the places in the Milky Way where life may exist. If people are looking for intelligent life outside our Solar System, Alpha of Centauri is an excellent candidate.

The Alpha of Centauri is located at a distance of 4.35 light-years from us. In fact, it is a triple star system. The two bright components, Alpha Centauri A and B, form a pair. They travel about each other for 80 years at a distance of 23 AU (1 AU = distance from the Sun to Earth). The third member of the system, Alpha Centauri C, is 13,000 AU away from A and B, or 400 times the distance from the Sun to Neptune. This is too long, so it is unclear whether C is actually connected to A and B or it has been torn off the system millions of years ago.

Currently Alpha Centauri C is closest to us – only 4.22 light years and is the closest individual star to the Sun. Because of this closeness, Alpha Centauri C is also called Proxima.

Alpha Centauri A is a yellow star with a spectral class G2, just like our Sun. Its temperature and color are the same as the Sun. Alpha Centauri B is an orange star with a spectral class K1. While Alpha Centauri A and B are similar to the Sun, Proxima is a timid, red dwarf with a spectral class M5 – very pale, cold and small to the Sun. Proxima is very dim, so it was not discovered until 1915 and despite its proximity can not be seen with a naked eye.

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