R136b
R136b is a Wolf-Rayet star in the R136 cluster in the Large Magellanic Cloud. It is one of the most massive and most luminous stars known. It is found in the dense R136 open cluster at the centre of NGC 2070 in the Tarantula Nebula.
R136b has a transitional spectral type between an O class supergiant and a Wolf-Rayet star, with a mix of absorption and emission lines. Although it shows enhanced helium and nitrogen at its surface, it is still a very young star, still burning hydrogen in its core via the CNO cycle, and still effectively a main sequence object.
