Var 83

Var 83 (also known as VHK 83) is a luminous blue variable star in the Triangulum Galaxy. It is the brightest nonstable star in M33 and is one of the most luminous stars known.

The brightness varies slowly and unpredictably and can remain approximately constant for many years. Temperature estimates for the star range from around 18,000K to well over 30,000K. The hotter temperatures found from fitting the spectral energy distribution (SED) are consistent with the calculated luminosity of an LBV in the quiescent stage, but the spectrum is that of a cooler star.