Probably from a Vulgar Latin *stēlum, from an interpretation of stēla (from Classical Latin stēlla) as a neuter plural, through analogy with other words such as Latin signa, sidera, and astra, respective neuter plurals of signum, sidus, and astrum. Ultimately from Proto-Indo-European *h₂stḗr. See also Catalan estela, and estrella.