Nunki is a hot blue star in the central regions of Sagittarius, in the belt of the Milky
Way. Like all Sagittarius' stars, it lies in the direction of the Galaxy's core, and
is also close by the line of the Ecliptic.
The mass of this star is comparable to that of the Sun (in other words, it lies among
the Main Sequence, or Dwarf, stars), although its surface temperature of about
8,000 K is roughly twice that of our own star. Nunki also differs from the Sun
in being a binary: in common with many stars, it has a fainter companion.
From Earth, Nunki has a magnitude of +2.1 (equivalent to Alpheratz or Mirach, both in Andromeda),
but this is largely due to its great distance, more than 200 light years from the
Sun. At ten parsecs (the standard for measuring absolute magnitude) it would shine
with a magnitude of -2.14, brighter even than Sirius.