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

A combining form with the meaning "pertaining to stars or celestial bodies" used in the formation of compound words. Variants aster-, and astr- before a vowel. → star.

Gk. astron "star," akin to L. stella (Fr. étoile, from O.Fr. esteile, from V.L. *stela), Skt. str-, tara-, Av. star-, Mid.Pers. star, stârag, Mod.Pers. setâré, axtar, see below; cf. O.E. steorra, E. star, Du. ster, O.H.G. sterro, Ger. Stern, PIE *ster- "star."

Mod.Pers. axtar, → star, from Mid.Pers. axtar. The variants star-, estâr, estâré, setâré are obvious. Note also the following dialectal forms: (Lori, Laki) âsâra, (Tabari) essâra, (Laki) hasâra, (Shughni) xiterj, xtarag. The form axtar is less straightforward, leading some philologists to suggest different origins for setâré and axtar. According to W. Eilers (Iranica), axtar is a back-fomation from Mid.Pers. apâxtar "planet; north" produced by artificial dropping of the first component. Apart from phonological difficulties inherent in this suggestion, one must also explain how axtar meaning "planet" became a general designation for star, as for example in Mid.Pers. axtarmâr "astronomer," despite the relatively infinitesimal number of planets known in ancient times. W. Eilers' suggestion is pure theoretical construction; no factual evidence support it. On the other hand, in Pahlavi texts, e.g. Bundahishn, axtar is extensively used for "star, planet, and the signs of zodiac."

We suggest that both words star and axtar are etymologically related. This idea is based on the fact that "s" and "x" phonemes interchange in Persian and other IE languages. For example, the PIE *swesor "sister" has evolved into Av. xvanhar-, Mid.Pers./Mod.Pers. xâhar (Skt. svasar-, L. soror, Fr. soeur, Gk. eor "daughter, cousin, relative," Arm. k'oyr, O.H.G. swester, Ger. Schwester, Du. zuster, E. sister). Similarly, *saewel- "sun" has become Av. hvar- "sun," Mid.Pers. xavr, Mod.Pers. xor, while keeping its Av. h in Mod.Pers. hur "sun" (cf. Skt. svar-, surya-, Gk. helios, L. sol, Goth. sauil, Lith. saule). Finally, *su- "hog, pig, swine" also has changed its "s" into both "h" and "x" in Av. and Mod.Pers. hu- and xuk respectively (Skt. sukara- "boar, hog, pig," Gk. hys, L. sus, Welsh hucc, Ger. Schwein, E. swine).