Luminous and Variable Stars in M31 and M33 V. The Upper HR Diagram
  We present HR Diagrams for the massive star populations in M31 and M33
including several different types of emission-line stars: the confirmed
Luminous Blue Variables (LBVs), candidate LBVs, B[e] supergiants and the warm
hypergiants. We estimate their apparent temperatures and luminosities for
comparison with their respective massive star populations and to evaluate the
possible relationships of these different classes of evolved, massive stars,
and their evolutionary state. Several of the LBV candidates lie near the LBV/S
Dor instability strip which supports their classification. Most of the B[e]
supergiants, however, are less luminous than the LBVs. Many are very dusty with
the infrared flux contributing one-third or more to their total flux. They are
also relatively isolated from other luminous OB stars. Overall, their spatial
distribution suggests a more evolved state. Some may be post-RSGs like the warm
hypergiants, and there may be more than one path to becoming a B[e] star. There
are sufficient differences in the spectra, luminosities, spatial distribution,
and the presence or lack of dust between the LBVs and B[e] supergiants to
conclude that one group does not evolve into the other.
