Borrowed from Old French estier.
stêr f
From Proto-Iranian *Hstā́ (compare Persian ستاره (setâre), Pashto ستوری (storay), Ossetian стъалы (st’aly), Avestan 𐬯𐬙𐬀𐬭 (star)), from Proto-Indo-Iranian *Hstar- (compare Sanskrit तारा (tārā)), from Proto-Indo-European *h₂stḗr (compare Latin stēlla, Tocharian A śre, English star).