An Etymological Dictionary of Astronomy and Astrophysics

The star that governs the solar system. It is a yellow main-sequence star of spectral type G2, shines with apparent magnitude -26.74, and has an absolute magnitude of +4.83. The Sun is 4.6 billion years old and lies 27,000 light-years from the Galactic center.

Etymology (EN): O.E. sunne; cf. O.N., O.S., O.H.G. sunna, M.Du. sonne, Du. zon, Ger. Sonne, Goth. sunno; cognate with Pers. xor, hur, as below.

Etymology (PE): Xoršid “sun,” originally “sunlight,” from xor “sun,” variant hur; Mid.Pers. xwar “sun;” Av. hū-, hvar- “sun;” cf. Skt. surya-, Gk. helios, L. sol, cognate with E. sun, as above;
PIE base *sawel- “sun” + šid “light, sunlight;” from Mid.Pers. šêt “shining, radiant, bright;” Av. xšaēta- “shining, brilliant, splendid, excellent.”