An Etymological Dictionary of Astronomy and Astrophysics

Any group or set of six. → Seyfert’s sextet.

Etymology (EN): From Latinized sestet, from It. sestetto, diminutive of sesto “sixth,” from L. sextus “sixth,” from sex,
→ six.

Etymology (PE): Šeštâyé, from šeš, → six,

• tâ “fold, plait, ply; piece, part” (Mid.Pers. tâg “piece, part”)
• -(y)é nuance suffix.