Nunki is Sigma Sagittarii, a hot blue main-sequence star of spectral type B2.5 at about 230 light years, the second-brightest star of Sagittarius. It stands in the handle of the Teapot, the familiar asterism that forms the body of the archer, in the small group sometimes called the Teaspoon. Its name is remarkable: Nunki is one of the very few star-names to come down from ancient Babylonian and Assyrian astronomy, revived in modern times from a cuneiform designation, a rare survival of the star-lore of Mesopotamia into the names in use today.
The cuneiform designation behind Nunki's revival is generally connected with a Babylonian name meaning something like the star of the proclamation of the sea, or of Ea, god of the sweet waters, part of the wider Mesopotamian tradition that gave the constellation of the Goat-Fish, Capricornus, to the same watery god; the identification rests on nineteenth and twentieth-century Assyriological reconstruction of star lists rather than on a continuous unbroken naming tradition. Sagittarius's Teapot asterism, though a purely modern popular pattern rather than any historical constellation figure, has become one of the most widely used naked-eye landmarks for locating the galactic centre, which lies just beyond the spout.