An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The closest star to the Sun, lying 4.24 → light-years away. Other designations: α Centauri C, GL 551, HIP 70890, or simply Proxima. It is the faintest of the three stars that make up the → Alpha Centauri system. Proxima Centauri is a → red dwarf of → spectral type M6 Ve. It has a magnitude of +11.0, but undergoes sudden brightness increases of up to 1 mag lasting several minutes. Proxima is a late-type → flare star with a rotation period of ~ 84 days. Its mass is about 0.123 → solar masses or 129 → Jupiter masses. Proxima orbits the binary system AB at a distance of about 15,000 → astronomical unit (AU)s, with a period of approximately 550,000 years (Kervella et al., 2016, arXiv:1611.0349). In about 200,000 years it will be at the same distance as AB and in 240,000 years it will be farther to Sun than AB. It has an → effective temperature of only around 3,050 K, a luminosity of 0.15 per cent of that of the Sun, a measured radius of 14 per cent of the radius of the Sun and a mass of about 12 per cent of the mass of the Sun. An → exoplanet, named → Proxima b, has been discovered orbiting our nearest neighbor star. Proxima experiences a seven-year activity cycle, similar to the Sun's 11-year cycle (B. J. Wargelin, B. J. et al., 2016, arXiv:1610.03447). But unlike the Sun's relatively moderate flares, Proxima's outbursts of X-ray and ultraviolet radiation could prove deadly for any hypothetical life on its planet, Proxima b.

Proxima, feminine of proximus "nearest," superlative of prope "near;" → approximate; → Centaurus.

Proksimâ, from L., as above; Kentâwros, → Centaurus; nazdiktarin, superlative of nazdik "near," from Mid.Pers. nazdik "near," from nazd "close" (Mid.Pers. nazd, nazdik "near," nazdist "first;" O.Pers. ašna- "close;" Av. nazdišta- "nearest, next," nazdyo "nearer to," nas- "to come near, approach, reach;" cf. Skt. nédīyas- "closer, very close," nas- "to approach, to reach") + -ik, → -ic.

→ Proxima b.

→ Proxima Centauri