HD 143183 is a red supergiant variable star of spectral type M3Ia in constellation Norma. It is a member of the Norma OB1 association, at a distance of about 2 kiloparsecs. It is one of the most luminous red supergiants with a luminosity over 100,000 times greater than the Sun (L☉), and is as well one of the largest stars with a radius more than a thousand times that of the Sun (R☉). Older studies frequently calculated higher luminosities and radii. It has an estimated mass loss rate of 5×10−5 M☉ per year and has been once described as a cool hypergiant. It is surrounded by a dozen early-type stars and a circumstellar nebula which extends 0.12 parsecs (0.39 ly).